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Approved For Release 2003/05/14: CIA-RDP78B04560A007300010028CONFIDENTIAL TECHNICAL PUBLICATION NATIONAL PHOTOGRAPHIC INTERPRETATION CENTER A GLOSSARY FOR COLOR AERIAL RECONNAISSANCE Declass Review by NIMA / DoD GROUP 1: EXCLUDED FROM AUTOMATIC DOWNGRADING AND DECLASSIFICATION CONFIDENTIAL NPIC/R-01/72 JANUARY 1972 Approved For Release 2003/05/14: CIA-RDP78BO456OA007300010028-8 Approved For Release 2003/05/14: CIA-RDP78BO456OA007300010028-8 This document contains information affecting the national defense of the United States, within the meaning of Title 18, sections 793 and 794, of the U.S. Code, as amended. Its transmission or revelation of its contents to or receipt by an unauthorized person is prohibited by law. Approved For Release 2003/05/14: CIA-RDP78BO456OA007300010028-8 Approved For Release 2003/05/14: CIA-RDP78BO456OA007300010028-8 CONFIDENTIAL NPIC/R-01/72 A GLOSSARY FOR COLOR AERIAL RECONNAISSANCE January 1972 NATIONAL PHOTOGRAPHIC INTERPRETATION CENTER Approved For Release 20cP05/11pA-~&78B04560A007300010028-8 Approved For Release 2003/05/14: CIA-RDP78BO456OA007300010028-8 CONFIDENTIAL NPIC/R-01/72 TABLE OF CONTENTS Page 1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . 2.0 GLOSSARY . . . . . . . . . . . . . . . . . . . . . 154 3.0 APPENDIX . . . . . . . . . . . . . . . . . . . . 161 4.0 REFERENCES . . . . ? ? ? ? ? ? ? ? ? ? ' ' ' ' , 155 FIGURE 1 HORIZONTAL SECTION OF THE EYE . . . . . . . . . . 156 FIGURE 2 CHROMATICITY DIAGRAM . . . FIGURE 3 DSPECTRAL IFFERENT EDIRECTIONS RAANDT UNDER DIFFERENT CONDITIONS AT CLEVELAND, OHIO . . . . . . . . . . . . . . . . . . . 15 7 FIGURE 4 LIGHT UNITS . ? ? ? ? ? ? ? ? ? ? ' ' ' ' ' 158 LIST OF TABLES 159 TABLE 1 CONVERSION TABLE . . . . . . . . . . . . . . TABLE 2 SUMMARY OF THE BETTER KNOWN COLOR VISION THEORIES . . . 160 Approved For Release 20091'9Y1iPCKTAb178B04560A007300010028-8 Approved For Release 2003j[Offt*f[K 8B04560A007300010 ?/R-01/72 This glossary attempts to define and describe in simple, under- standable language a set of words, concepts, and measures related to color aerial reconnaissance. The purpose of the glossary is to provide a reference which can be used to learn and understand basic terminology related to color-aerial reconnaissance and to help improve communication 'concerning color. For maximum usefulness several criteria were used to guide and limit the compilation and writing of the glossary: 1. The words chosen and their definitions should be relevant to color as it relates to aerial reconnaissance. Since aerial reconnaissance is broad, the Glossary is broad, covering terminology from color aerial photography (its acquisition, processing, and interpretation), and from the psychology, physiology, physics, and measurement of color. Yet within these broad categories there are gaps in terminology which are not related to aerial reconnaissance. Thus the reader should not expect to find a complete and comprehensive glossary on Color. 2. The language (terms and concepts) of the glossary should be easy to understand so that a wide range of personnel in aerial reconnaissance could read and understand the material included. For those who wish or need to know greater technical detail, theory, or procedures there are a number of excellent references in all technical areas. 3. Extraneous words and concepts should be omitted so that the material can be presented in a succinct manner. To help satisfy these criteria, a review of the major literature in aerial reconnaissance and in related technical fields was performed and major sources, e.g., technical textbooks, manuals, glossaries, and dictionaries were selected for use. These sources were then searched for relevant words, concepts, and measures, resulting in over 1,000 terms to be included. Each term had at least two or three definitions, so the most appropriate one had to be chosen. Then, if necessary, it had to be Approved For Release 2003/QN F [IIkB04560A007300010028-8 Approved For Release 20e3' I6E Gl~,-P, P78BO456OA0073000 $~r-01/72 rewritten in order to adhere to the prescribed format (discussed below). In addition, figures, tables, and added explanations in the form of "Notes", were used to help clarify the definitions and aid in reader understanding. Important aspects of the Format are enumerated below: (1) The terms are arranged in alphabetical order and are capitalized. Following certain terms one or more synonyms will appear in parentheses. Reference numbers in brackets also will be used if the definition has been taken from the source, either verbatim or slightly modified. (2) Under each term is the definition, and if more than one definition is used, they are enumerated. Within a definition, important words, if also defined in the glossary, are capitalized. (3) Following the definition(s) there may be a "Note" which is used for additional explanation and illustration. (4) Finally, a "See Also" is used when the reader should refer to another glossary word for further explanation. All major figures and tables are found in the Appendix and a general reference list is included which contains the major sources for the glossary. Approved For Release 2CONHQEitL,bP78B04560A007300010028-8 Approved For Release 2003/0~ ti i~~R,78B04560A0073000100 I /R_01/72 ABAXIAL [4] 2.0 GLOSSARY A ABERRATION [12] A ray of light that does not coincide with the OPTICAL AXIS. A marginal ray passing through a lens. Note: See Figure below, light ray x is ABAXIAL. ABBE NUMBER [8] The number expressing the extent to which the shorter and longer wavelengths of light are separated by refraction through a particular The failure of an optical system to bring all light rays received from a point object to a single image. Note: Defects in the performance of a lens or mirror which prevent it from giving an absolutely sharp image. In practice the complete removal of all aberra- tions is impossible. The aberra- tions inherent in any optical system are listed below. See Also: CHROMATIC ABERRATION; SPHERICAL ABERRATION; COMA; CURVATURE OF FIELD; ASTIGMATISM; and DISTORTION glass, i.e., the amount the glass ABNEY EFFECT disperses the various colors. The greater the number, the smaller the dispersion, i.e., the less the separation of the colors after refraction. In practice they vary from about 25.5 for Double Extra Dense Flint glass to 60.3 for Hard Crown glass. Note: The Abbe Number is (nD-1)/ (nF-nc) where n is refractive index and the subscripts indicate measurement at the sodium D line (589 nm), the hydrogen F line (486 nm), and the hydrogen C line (656 nm). The change in apparent HUE which may occur when SATURATION is changed. A compromise to true SPECTRO- PHOTOMETRY in which a set (often 10-16) of narrow-bandpass filters (5-20-nm half width) is used to provide an approxima- tion to the complete spectrophoto- metric curve. Approved For Release 2003/ FM),fiM1 I kB04560A007300010028-8 Approved For Release 2I6 tk J~pP78BO456OA0073000' %81_01/72 ABSOLUTE TEMPERATURE [4] A temperature with the Kelvin (K) scale, having degrees the same size as Celsius (Centigrade) and zero placed at approximately -273 C. Thus 0 C. = 273 K. 100 C.= 373 K. ABSORBANCE, SPECTRAL Absorbance at a specified wave- length. ABSORBANCE [5] (ABSORPTION FACTOR) Logarithm (to the base 10) of the ratio of the light (LUMINOUS FLUX) incident on a transparent body, to that emerging from it. Preferred to DENSITY or OPTICAL DENSITY. Light which is converted into heat when passing through a body. ABSORPTION (SELECTIVE ABSORPTION) The dissipation of light into heat when passing through a medium. The remaining light is either TRANSMITTED or REFLECTED. Note: Color of objects is the result of selective absorption of certain wavelengths. If white light falls on a surface that absorbs the red and green rays, the surface appears blue to the eye because that is the only visible light reflected by the surface. If white light passes through a transparency that absorbs all wavelengths but red, the transparency will be perceived as red. ABSORPTION BAND (ABSORPTION LINE) [4] The dark band or line in the spectrum or SPECTROGRAM caused by the failure of the material that is being analyzed to transmit light of that wave- length. Note: For example, a yellow filter will not transmit a certain portion of wavelengths in the blue region. The SPECTRO- GRAM of the yellow filter would show dark lines at those wave- lengths. ABSORPTION COEFFICIENT See ATTENUATION COEFFICIENT ABSORPTION CURVE 18] Graphic representation of the ABSORBANCE of a medium, plotted against the wavelength of the light. Generally used to give an indication of the characteris- tics of color filters and dyes in color films. Note: The Figure below is an Absorption Curve for a yellow filter (minus-blue filter). 500 600 700 Wavelength, nm Approved For Release 2O'$ ?E N1 AtP78B04560A007300010028-8 Approved For Release 2003/A [N4j 5lA-F Lj [8 B04560A0073000100R?*/R-O1 /72 ABSORPTION FACTOR See ABSORBANCE ACCELERATOR A term often applied to the alkaline constituent of a developing solution because increasing the amount of alkali in all normal cases speeds up the action of a developer. (1) The faculty of the human eye (lens) to adjust (focus) in order to render sharp images for different object distances (4 to 5 inches to infinity). (2) The ability of the eyes to bring two images into superimposi- tion for stereoscopic viewing. (1) Lacking in HUE and SATURATION, and varying only in BRIGHTNESS, or LIGHTNESS, e.g., black, white, or any gray. (2) When applied to a lens, it means that the lens has been corrected for CHROMATIC ABERRATION at two wavelengths. See Also: ACHROMATIC LENS ACHROMATIC COLOR [5] Color perceived to have no HUE. Note: Examples of Achromatic Color are black, gray, white, and "clear, colorless". ACHROMATIC LENS (ACHROMAT) [4] A lens that is corrected for chromatic aberration at two wave- lengths of light. A lens that is customarily made to bring green and red light rays to approximately the same point focus. Note: Such a lens is not suffi- ciently corrected for color photography, ADDITIVE COLOR SEPARATIONS, or COLOR SEPARATION NEGATIVES See Also: APOCHROMATIC LENS ACHROMATIC LIGHT [5] Light perceived as having no HUE. ACHROMATIC OBJECT [11] An object that reflects or transmits the same proportion of light at each wavelength. Thus, appearing ACHROMATIC, e.g., black, white, or grays. ACHROMATIC POINT [5] Point in the CHROMATICITY DIAGRAM in the CIE color system used as the basis for determination of DOMINANT and COMPLEMENTARY WAVE- LENGTHS and for EXCITATION PURITY because it represents the CHROMATICITY of a color which is acceptable as achromatic under the conditions in which the colors are observed. Usually, the chromaticity of the illuminant is used for this point. Approved For Release 2003/OcQ)1:F RDJP'19BO456OA007300010028-8 Approved For Release 2T (05116EG R. pP78B04560A0073000VMIR-01/72 ACHROMATIC POINT [5] (Continued) Note: See Figure 2 in the Appendix. The center of the circle denoted as "WHITE" is the Achromatic Point. ACHROMATIC REGION [5] The part of a CHROMATICITY DIAGRAM in the CIE Color System that rep- resents ACHROMATIC COLORS under circumstances of common occurrence. Note: See Figure 2 in the Appendix. The area inside the circle denoted as "WHITE" is the Achromatic Region. ACHROMATOPIA (ACHROMATOPSIA, ACHROMATISM) [5] Type of MONOCHROMATISM in which all colors are perceived as achromatic or total color blind- ness. ACTINIC LIGHT [4] ACUITY, VISUAL [4] A measure of the eye's ability to separate details in viewing an object. The reciprocal of the minimum angular separation, in minutes of arc, of two lines of detail which can be seen separately. ACUTANCE [4] A complex, objective measure of the ability of a photographic system to show a sharp edge between continuous (touching) areas of low and high. The degree of sharpness and con- trast of edges in an image. The faculty of the human eye to adjust its sensitivity to varying intensities and colors of illumina- tion. A part of the spectrum (usually infrared, visible, and ultra- See Also: ADAPTATION, DARK; violet wavelengths) that causes ADAPTATION, LIGHT; AND ADAPTATION, chemical changes to occur CHROMATIC in light sensitive photographic emulsions. The light that creates ADAPTATION, CHROMATIC images on light sensitive material. The blue or violet portion of the The faculty of the human eye to spectrum would be the actinic band adjust its sensitivity to of light for blue or violet differences in HUE and SATURATION, sensitive photographic materials. or colors. ACTINOMETER [4] An instrument for measuring the ACTINIC value of light according to a given scale. Note: When staring at a single color, the eye adapts to it; but upon looking at another color, the eye must adapt again before the color will be perceived optimally. Approved For Release 2&0/hI NI bP78B04560A007300010028-8 Approved For Release 2003,LQ51a f 1b tIV I IA? 8B0456OA007300010998r@/R-01/72 ADAPTATION, CHROMATIC (Continued) However, this adaptation occurs relatively quickly. ADAPTATION, DARK The faculty of the human eye to increase its sensitivity to reduced illumination. Note: In total darkness, dark adaptation takes 30 to 45 minutes, although-in 15 minutes sensitivity has increased significantly. ADAPTATION, LIGHT The faculty of the human eye to lower its sensitivity to increased illumination. Note: Light adaptation occurs in a few minutes. A COLOR MATCHING procedure in which the standard is varied by adding various proportions of different colors. See Also: THREE-COLOR MIXTURE; NEGATIVE COMPONENT IN COLOR MIXTURE The principle that most colors can be formed by mixing the lights of two or more other colors. A method for reproducing all colors using the principle of ADDITIVE SYNTHESIS. Usually, black-and-white positive transparencies are acquired through the primary color filters (blue, green, and red), and are projected and viewed in register by means of light beams of the same primary colors. ADDITIVE SYNTHESIS (ADDITIVE COLOR MIXTURE) 151 The formation of a color by mixing light of two or more other colors. Most colors may be formed by mixing light of three conveniently select- ed primary colors (blue, green, and red) in the proper proportions. Some colors may be formed by mixing light of two colors. Note: For example, a mixture of blue and green lights produces CYAN, a mixture of blue and red lights produces MAGENTA, and a mixture of green and red lights produces YELLOW. See Also: NEGATIVE COMPONENT IN COLOR MIXTURE Approved For Release 2003/&`4 FkDihkEl* BO456OA007300010028-8 Approved For Release 20~ (W~itt~ t-,gIC78BO456OA00730001R$?PA-01/72 ADJACENCY EFFECTS AERIAL EXPOSURE INDEX (A.E.I) [4] When two adjacent areas of an image receive exposures of different magnitude, their respective densities and the position of their common boundary may not reflect the exact distribu- tion of light within the emulsion at the time of exposure. The results are known as Adjacency The reciprocal of twice the exposure, expressed in meter- candle-seconds, at the point of the TOE of the CHARACTERISTIC CURVE where the slope equals 0.6 gamma when recommended processing and exposure conditions are used. Effects. In color materials, AFFECTIVE COMBINATION, LAW OF [6] during processing, the DEVELOPMENT products may diffuse away from the silver halide grains and react with the-DYE COUPLER to form a dye image at some distance from the silver image. The secondary dye image improves edge definition, but also produces objectionable halos. Color fringing may also occur as a result of unequal effects in the several dye layers. ADVANCING COLORS [5] There are WARM COLORS (typically reds) which are perceived, or tend to be perceived, leaving the picture plane or physical plane and approaching nearer to the observer. Note: When viewing color transparencies or prints, the objects imaged as "warm colors" may appear to stand out from the image. During stereo viewing this may cause exaggerated heights. The "pleasantness" value of a combination of colors is highly dependent on the "pleasantness" of the component colors. This law holds for CHROMATIC as well as ACHROMATIC colors. AFTER-IMAGE (AFTER-SENSATION) A visual sensation occurring after stimulation has ceased which was caused by and appears as the previous stimulation. Note: Staring at a target on film for many seconds (time varies between individuals) can cause an after-image of that target and interfere with subsequent viewing. See Also: AFTER-IMAGE, NEGATIVE; AFTER-IMAGE, POSITIVE; AFTER- IMAGE, PURKINJE AFTER-IMAGE, HERING [5] The first POSITIVE AFTER-IMAGE which occurs following a brief light stimulus. Approved For Release 2c@O I ENl IAtP78BO456OA007300010028-8 Approved For Release 2003/ebf:I b F 18BO456OA0073000100 k/R-01 /72 AFTER-IMAGE, NEGATIVE (COMPLEMENTARY this image is never simply a point, AFTER-IMAGE) but a small disk, no matter how perfect the lens. A visual after-image in which black and white shades are reversed and AIRY RINGS the colors are usually approx- imately COMPLEMENTARY to those The rings (or diffraction patterns) of the original response. surrounding the AIRY DISK caused by the DIFFRACTION characteristics AFTER-IMAGE, POSITIVE (HOMOCHROMATIC of the optical system. AFTER-IMAGE) A visual after-image in which black and white shades are the same and The ratio of reflected-to- the colors are approximately the incident light. same as those of the original response. Note: This ratio for any one surface is independent of the AFTER-IMAGE, PURKINJE intensity of light source. A visual after-image in which black ALCOHOL, ABSOLUTE and white shades are the same and the colors are approximately Chemically pure ethyl alcohol COMPLEMENTARY to those of the without water. original response. Ag. Chemical symbol for silver. AGITATION [4] ALCOHOL, DENATURED Ethyl alcohol rendered unfit for drinking by the addition of agents known as denaturants. Almost all industrial alcohol is denatured. The process of circulating the photographic solution in which the ALCOHOL, METHYLATED film or paper is immersed. To bring fresh solutions into contact English term for one kind of with the emulsion. Bubbling denatured alcohol. nitrogen through the solutions is a commonly used method of agita- ALTITUDE tion. AIRY DISK [4] Vertical distance of an object or point above DATUM, usually mean-sea-level. The image of an infinitely distant point as focused on a plane by a diffraction limited lens. Because of the wave structure of light, Approved For Release 2003IEf)Nf:I@ Ai8B0456OA007300010028-8 Approved For Release 2ffl3 -gll'I,At.M-FtAP78BO456OA0073000 " 01/72 ALYCHNE The line or locus of points on the CIE CHROMATICITY DIAGRAM that corresponds to the CHROMATICITY COORDINATES of the normal colors that have zero luminosity. By locating two of the three CIE PRIMARIES at the extremes of the alychne the CIE Committee made the CIE y color-matching function identical with the PHOTOPIC CURVE of the STANDARD OBSERVER. This was done to facilitate the computation of photometric quantities from color matching data. Loss of sight due to defect of the optic nerve which is not accompanied by any perceptible change in the eye itself. Dimness of vision for which no organic defect in the refractive system of the eye has been discovered. Note: Found in total color- blindness, in albinism, in toxic conditions, and is associated with the excessive use of drugs. AMERICAN NATIONAL STANDARDS INSTITUTE See ANSI Old name for what is now the American National Standards Institute. See ANSI. A stereogram in which the two views are printed or projected super- imposed in complementary colors, usually red and green. By viewing through filter spectacles of corresponding COMPLEMENTARY colors, a stereoscopic image can be viewed. Analogous colors are those which have some perceptible similarity or close relationship with respect to one or more of the attributes of color; as, closely related in HUE, or BRIGHTNESS, or SATURATION. Note: Usually the term refers to the relation of hues alone; as, reds and oranges or greens and yellow-greens are called Analogous hues or colors. ANALYTICAL DENSITOMETRY (ANALYTICAL DENSITIES) A means of determining the amounts of the individual colorants (CYAN, MAGENTA, and YELLOW dyes) in an element of a photographic image. Note: There are three types of Analytical Densities (see also): ANALYTICAL SPECTRAL DENSITY; EQUIVALENT NEUTRAL DENSITY; and EQUIVALENT NEUTRAL PRINTING DENSITY. ANALYTICAL SPECTRAL DENSITY (ASD) The density of a single dye or colorant at a single wavelength. Note: In color films, it is a measure of the amount of dye deposit in a dye layer. Approved For Release 2( ll)ENq * P78BO456OA007300010028-8 Approved For Release 2003{1'gf i ypgf8BO456OA0073000100Ri8I?/R-01/72 A lens which does not magnify equally along mutually perpendic- ular axes. A lens which has been corrected for ASTIGMATISM. ANASTIGMATIC LENS [4] See ANASTIGMAT ANGLE The difference in direction between two intersecting lines. Note: The unit measures of an angle are the Degree (the 1/360 part of a circle) or the Radian (the angle resulting when the length of an arc is equal to its radius). 1 Radian = 57? 17' 44". ANGLE OF COVERAGE [4] The apex angle of the cone of rays passing through the front NODAL POINT of a lens. Lenses generally are classified according to their angles of coverages, as follows: narrow-angle -- Less than 60? normal-angle -- 60? to 75? wide-angle -- 750 to 1000 super-wide angle or ultra-wide angle -- Greater than 1000 0 ANGSTROM UNIT (A) [4] An old unit of measure for the wavelength of light, equal to one 'tenth of a manometer: for example, the visibleospectrum gxtends from about 4,000A to 7,000A (400 to 700 nanometers) . An apparatus for determining color deficiencies in human vision. ANOMALOUS TRICHROMATIC VISION (ANOMALOUS TRICHROMATISM) [5] A form of defective color vision in which three primaries are required for color matching, but the proportions in which they are matched differ significantly from those required by the NORMAL TRICHROMAT. Note: Generally these people can see all colors but are weak in a particular color. There are three forms of Anomalous Trichromatism -- PROTANOMALOUS, DEUTERANOMALOUS, and TRITANOMALOUS VISION. They cover the ranges of defective color vision lying between normal trichromatism and complete PROTANOPIA, DEUTERANOPIA, or TRITANOPIA, respectively. See Also: PROTANOMALOUS VISION; DEUTERANOMALOUS VISION; TRITONOMALOUS VISION American National Standards Institute, formerly United States of America Standards Institute (USASI), and before that American Standards Association (ASA). Approved For Release 200316f)W-ISI 8BO456OA007300010028-8 Approved For Release 2Q Adityl6tkLftRpP78BO456OA0073000 ,8 _01/72 ANSI (Continued) Because of widespread usage, some ANSI standards retain the designa- tion ASA as in ASA speed. ANTI-FOGGING AGENT (ANTIFOGGANTS; FOG RESTRAINERS) Chemical included in a DEVELOPER or EMULSION to retard the forma- tion of development FOG. ANTI-HALATION BACKING [4] A light-'absorbing coating applied to the back side of the support of a film or plate (or between the EMULSION and the SUPPORT) to suppress HALATION. Very thin coating of a metallic fluoride applied to a glass surface -- e.g., of a lens -- to reduce light lost by reflection. The most commonly used anti- reflection-film material is magnesium fluoride, MgF2. Note: Color images taken without this filter will have darkened corners and edges. However, these filters are often not used because they reduce the overall light level. See Also: VIGNETTING APERTURE-COLOR PERCEPTION [5] Perception of color as filling an aperture in a screen. Note: An aperture-color percep- tion is non-located in the sense that it may be near the plane of the screen or indefinitely far behind it, but it tends to be seen closer to a plane perpendic- ular to the line of sight. It has a filmy, soft character in contrast to a SURFACE-COLOR perception which has a hard character corresponding to an exact location in space. See Also: FILM-COLOR APERTURE An opening or hole through which light or matter can pass. See Also: APERTURE, EFFECTIVE A filter to correct variations in illumination across the focal APERTURE, EFFECTIVE [4] plane.. The rear of the filter (over the lens) is coated with The useful area of the opening neutral material whose DENSITY through which the ray of light gradually decreases from the center passes to the film to produce toward the edges to cut down the the image. exposure of the center portion. Approved For Release 206O iWENXM P78BO456OA007300010028-8 Approved For Release 2003/ FpJ ' B0456OA007300010021$P C/R-01/72 APERTURE, NUMERICAL The sine of the half angle of the widest cone of light rays capable of being transmitted through a lens system, multiplied by the INDEX OF REFRACTION of the medium in which the object is embedded. APERTURE STOP [4] The physical element (such as a stop, DIAPHRAGM, or lens periphery) of an optical system which limits the size of the pencil of rays traversing the system. The adjustment of the size of the aperture stop of a given system regulates the brightness of the image without necessarily affecting the size of the area covered. APERTURE, WORKING [4] The largest DIAPHRAGM opening at which a lens diaphragm can be set. APOCHROMATIC LENS [4] A lens which is corrected for CHROMATIC ABERRATION at three wavelengths (blue, green, and red) of light rather than two, as in the ACHROMATIC LENS (green and red). APOLSTILB (asb) (METER-LAMBERT) A unit of LUMINANCE equivalent to 1 candela/meter2. Note: See Table 1 in the Appendix. APTITUDE, COLOR See COLOR APTITUDE APPEARANCE PLAN A method of developing color systems in which the intervals on the dimensions of colors are based on human judgment. The MUNSELL COLOR SYSTEM is an example. AQUEOUS HUMOR [11] A clear liquid (Specific Viscosity = 1.03) which fills the chamber between the CORNEA and the LENS. Note: See Figure 1 in the Appendix. Densities measured with a DENSITO- METER whose responses do not conform to any particular colors or density measuring conventions. Any combination of filters or photo tubes may be used. AREA EFFECT [6] A change in color of an object as it varies in size (independent of distance) on the retina. Note: As the area increases (up to 20 degrees subtended on the retina and under most conditions) so does saturation. Past 20 degrees the color becomes progressively less saturated. Approved For Release 2003/FWRLB04560A007300010028-8 Approved For Release 2(4 f + ft DP78BO456OA00730001a $1801/72 Any illumination not produced by the sun but which has a wide range of wavelengths, generally appearing white. See Also: INCANDESCENT TUNGSTEN LIGHT; FLUORESCENT LIGHT ASA [ 41 American Standards Association, now reorganized under the name American National Standards Institute (ANSI). ASA (AMERICAN STANDARDS ASSOCIATION) COLOR MEASUREMENT METHOD (Z58.71- 1951) Commonly used method of measuring color by spectrophotometry followed by calculation of CIE tristimulus values (see TRISTIMULUS VALUES, definition 2). ASA SPEED [8] System of rating the speed of sensitized materials laid down by the American Standards Association (now ANSI) in the ASA standards PH2.5 -- 1960 for black-and-white negative materials and PH2.21 -- 1961 for color reversal materials. The ASA speed for black-and-white negative emulsions is based on measurement of a prescribed point of the CHARACTERISTIC CURVE which is at a minimum density level above base + fog density and satisfies certain conditions of slope. The ASA speed can be expressed either as an arithmetical speed -- e.g., ASA 100 -- or in a logarithmic form where each successive step represents a change in sensitivity by a factor of 2 -- e.g., ASA 5?. This form distinguishes the ASA speed from the older, numerically similar exposure index figure. With reversal color films, the speed is based on the CHARACTERISTIC CURVES of the three dyes but is expressed in the same way. !Numerically, ASA speeds are identical with B.S. (British Standard) speeds as specified by B.S. 1380: 1962. In complex patterns, colors evoked by small, spatially juxtaposed areas may appear more alike than different. When judging or naming colors, adjacent colors may cause perceptual errors; therefore, it is better to isolate the colors being judged or named. A defect or aberration of an optical system which results in lines perpendicular to one another in the object plane being focused in different image planes. Note: In the Figure below is an example. Approved For Release 2 M ENI4.bP78BO456OA007300010028-8 Approved For Release 2003jNtra*1 78BO456OA007300010 ?/R-01/72 The absorption and scattering of light as it passes through the atmosphere. The attenuation affects the various wavelengths of light differently. See Also: RAYLEIGH SCATTERING; MIE SCATTERING See Also: RAYLEIGH SCATTERING; MIE SCATTERING Variations in the density of the air caused by variation in temperature and air pressure. I = amount of light re- maining k = attenuation coefficient Each material has a different attenuation coefficient at each wavelength. Note: The loss can result from scattering, absorption, or both. When the only loss is that due to absorption, the term Absorption Coefficient (similarly defined) is used. ATTITUDE [4] The angular orientation of a platform or of the photograph taken with that platform with respect to some external reference system. Usually expressed as PITCH, ROLL, and YAW. Note: Degrades high-altitude imagery by distorting the image as ATTRIBUTES OF COLOR (DIMENSIONS OF it passes through the atmosphere COLOR) [5] and reduces resolution. Further- more, atmospheric turbulence tends to degrade the small image details or higher spatial frequencies more than it degrades the gross features or lower spatial fre- quencies in the image. The CHROMATIC colors have the attributes of HUE, SATURATION, and BRIGHTNESS or LIGHTNESS, but the ACHROMATIC colors do not have those of hue and saturation. All colors have the general attributes of duration, location, and extent, but these are rarely mentioned. It is the proportionality constant AUBERT-FORSTER LAW [5] that relates the amount of light lost (EI) from a beam of light to the amount of light (I) that remains after the beam has traveled a distance (Ax) in the material, that is, AI = -kIOx where tI = amount of light lost Ax = distance traveled A generalization from the Aubert- Forster phenomenon, namely, that VISUAL ACUITY of a near object in the periphery is greater than that of a similar, distant object, even though the latter is large enough to subtend the same visual angle as the near object. Approved For Release 200 DE1NNl78B0456OA007300010028-8 Approved For Release 21f/ffa6tkIftgpP78BO456OA0073000' -01/72 AVERAGE GRADIENT AXIS, VISUAL A measure of contrast for a speci- An imaginary line from the object fied portion of the CHARACTERISTIC through the NODAL POINT of the CURVE, (slope of the line between eye to the FOVEA. any two points on the curve). There are no widely accepted definitions of the two points; therefore, they should.be specified. Note: In the figure below, the slopes A and B and C and D are Average Gradients. U) 3.0- 01 log (E) AVOIRDUPOIS WEIGHT (AVDP) 1.4J The system of weights in general use in the United States. The avoirdupois pound is defined as 453.5924277 grams. The smallest unit of the system is the grain, 7,000 equal one pound; the next larger unit is the dram, 256 equal one pound; the next larger unit is the ounce, 16 equal one pound. AXIS, OPTICAL (PRINCIPAL AXIS) [4] In a lens element, the straight line which passes through the centers of curvature of lens surfaces. In an optical system, the line formed by the coinciding principal axes of the series of optical elements (lenses). Approved For Release 2O1 f F1ID MP78B04560A007300010028-8 Approved For Release 2003! I: (? lffp}P.78BO456OA007300010( @/R-01/72 cu FA L BACK FOCUS (BACK FOCAL LENGTH) [4] pressure is 760 mm of mercury or 29.92 inches of mercury at 15 C Term used to designate the (59 F). distance between the back surface of a lens and the aerial image when BEAM the camera is focused at infinity. BAFFLE [4] A shaft or column of light, a bundle of rays. Used for the absorption of stray light within a camera or other optical instrument. BALANCE, COLOR See COLOR BALANCE BAROMETRIC ADMITTANCE [4] The transmission of ULTRAVIOLET LIGHT from the sun is inversely proportional to the BAROMETRIC PRESSURE. Thus, at high altitudes where the pressure is low, trouble is often experienced with the excessive proportion of ultra- violet light. The ultraviolet light admittance at 29.92 inches of mercury (sea-level) is regarded as the standard. Note: In high-altitude photography UV is usually not a particular problem since the camera faces toward the earth and the UV has been absorbed by the air column. However, at oblique angles the problem could arise. BAROMETRIC PRESSURE [4] The pressure of the atmosphere ex- pressed in inches of millimeters of mercury column height. At sea- level, the average barometric An optical device for dividing a light beam into two separated beams (e.g., a partially silvered mirror). Usually, there must be a color correction made because the beam splitter may be wavelength sensitive; thus, changing the color of the transmitted and reflected light. Note: In ADDITIVE COLOR SEPARA- TIONS the beam splitter is used to transmit a portion of the light to one film and reflect a portion to another film. Selective filters may be placed in front of each film. BEER'S LAW [6] (1) Stated formally: for a molecularly dispersed colorant of a given thickness, the amount of transmitted flux (It) of single-frequency light of wave- length X is a function of the amount of incident flux (I0)1 the extinction coefficient (ax) and the concentration (c) of the medium. Approved For Release 2003/6IF 8lE BO456OA007300010028-8 Approved For Release 20pVIVEf I IALP78B04560A00730001 ? 8j?-01/72 It = Ioe-a ac (2) A mathematical expression re- lating transmittance of a single wavelength through a colored medium to the INCIDENT FLUX, extinction coefficient, and the concentration of the medium. BEZOLD-BRtCKE PHENOMENON A change in hue resulting from a change in LUMINANCE. As luminance increases, colors which are orange or yellow-green appear yellower and colors which are purple or blue-green appear bluer. The colors of blue, green, yellow, and red generally remain the same. Note: If the luminance (such as that from a light table) remains the same during color viewing or naming, the effect will not be a problem. BINOCULAR COLOR MIXTURE [5] BINOCULAR FLICKER [5] Flicker evoked by rapidly alternat- ing presentation of stimuli to the right and left eyes, usually in such a manner that the gaps in the stimulus presented to one eye are filled by the stimulus presented to the other. BINOCULAR FUSION [5] The combination of two images falling upon the two retinas forming a single visual impression. The .images may be alike or may differ to some degree in form and color. Note: Stereoscopic viewing is an example of BINOCULAR FUSION. BINOCULAR MATCHING [1] The matching of stimuli, such as colors, by presenting the two stimuli to be matched to the right and left eyes respectively, and, ideally, having them occupy the two halves of a combined visual field. To avoid BINOCULAR FUSION The presentation of different colors of the two stimuli, fixation to corresponding areas of the two 'points should be provided. retinas, resulting in a single fused impression. This effect occurs BINOCULAR RIVALRY (RETINAL RIVALRY) only under special conditions, often the effect is BINOCULAR RIVALRY. Alternating sensations, first Note: During stereo viewing, if the two images are slightly different in color (which is normally true due to change of acquisition angle), the colors may be fused or the colors will alternate in dominance. from one eye and then from the other, when the two eyes are simultaneously stimulated by different colors or figures. Approved For Release 20EEN44[jp78B04560A007300010028-8 Approved For Release 2003Mflf l fttypjjk[78BO456OA007300010 ~/R-01/72 BINOCULAR RIVALRY (RETINAL RIVALRY) BLACK (Continued) Note: For example, if one eye is presented with blue and the other red, one can get the sensation of blue, then red, then blue, and so' on. In stereoscopy, if the color of one image is different from the other, this effect can occur. BINOCULAR VISION [5] Vision with the two eyes operating conjointly, usually with fixation of both on the same objective point. In general, characterized by a single perception of the objects fixated. An important factor in perception of space, giving projection and depth. See Also: MONOCULAR VISION (for comparison) A film consisting of two layers, each layer sensitive to a different portion of the SPECTRUM. (1) Total (or near total) absence of reflected light (2) The ACHROMATIC COLOR of minimum lightness or brightness. A phrase used to denote Kodak Infrared Aero Film 5424 which is a negative material of average resolution, sensitized to IR radiation, as well as to the visual spectrum. Should be used with a Wratten 89 B filter to cut out visible wavelengths. BLACKBODY [8] Theoretically, a perfect source of (radiant energy) and a body which absorbs all RADIANT ENERGY striking it. The conception of such a hypothet- ical reference source is found useful in stating the SPECTRAL POWER DISTRIBUTION of light or COLOR TEMPERATURE (in photog- raphy). Note: Most color films consist of three layers and are called TRIPACKS. The first layer of nerves leading away from the RODS and CONES towards the front of the eye. Activity in this layer is passed on to the next layer, GANGLION CELLS, at the junction called SYNAPSES. When a solid substance is heated, it glows first dull red, then brighter red, and finally white. Discounting any light reflected from the surface, the power distribution of the radia- tion emitted by the substance depends on the temperature to which it is heated. This is completely true for a blackbody -- i.e., one which reflects no light falling on it. Approved For Release 2003166V'Rl 1 n678BO456OA007300010028-8 Approved For Release 20ed.,16ENhftg~P78BO456OA0073000 t?-01/72 BLACKBODY [8] (Continued) solely by the temperature of the radiating body. In experimental physics such a blackbody is obtained by cutting a BLACK CONTENT circular opening in one side of a hollow, metal sphere. Owing to the In the OSTWALD COLOR SYSTEM, B is shape of the body, most of the light the BLACK CONTENT in the equation entering the opening is absorbed inside the sphere and virtually none emerges again. This aperture is therefore black--i.e., the "blackbody"--and, upon heating the sphere, the light emerging is W + B + C = 1, which OSTWALD considered as describing the appearance of all related colors. solely composed of radiant power BLACK LIGHT [8] due to the heating. The spectral power distribution of any incandescent light source can be stated in terms of the absolute temperature at which a blackbody emits rays of the same WAVELENGTH DISTRIBUTION. This temperature is referred to as the COLOR TEM=PERATURE of the LIGHT. Apart from the above mentioned sphere, there is no such thing as a perfect blackbody; all substances Black light is the name for ultra- violet illumination when it is used to make objects visible in the dark. The objects are treated with a dye or pigment which fluoresces under the ultraviolet radiation. The source consists of a mercury arc or other suitable light screened by a filter (e.g., covered with a lacquer) which cuts out all the visible rays but the ultraviolet. .reflect a certain amount of light BLEACH which mixes with that emitted on heating. So the spectral composi- tion of the light they emit is not absolutely proportional to their temperature. In many cases, however, the discrepancy is not serious. (1) To make whiter. (2) A chemical used for bleaching. (3) In color processing, a solu- tion that changes all developed sil- ver into soluble silver salts for later removal. (4) In black and white processing, a solution to remove developed silver. Part of the process of changing from a negative to a Radiant power emitted from a black- positive transparency. body and having the SPECTRAL POWER DISTRIBUTION given by PLANCK'S LAW, i.e., a distribution determined Approved For Release 20?kFWfM;E P78BO456OA007300010028-8 Approved For Release 2003ol FRX[8BO456OA00730001009PA/R-01/72 BLEACHING [8] Note: See Figure 1 in the Appendix. Converting a silver image BLISTERS [4] (negative or positive) into a more or less colorless silver compound, Small bubbles formed under the such as silver chloride, bromide, emulsion due to the detachment iodide, or complex salts containing of the emulsion from the paper or chromates, ferrocyanides, etc., of film. other metals as well. Bleaching forms the initial stage of a large Bubbles, elliptical in shape and number of toning processes for larger than one-quarter inch. transparencies and prints (where the additional metal compounds BLOCKED UP [4] often produce the color of the toned image), as well as many Applied to highlights in a photo- intensification methods. graphic negative which are so BLEACH-OUT PROCESS [5] overexposed or overdeveloped that no detail is visible. A process for making color prints BLOOM 151 from a color transparency, by using a support coated with a mixture of dyes, each of which is capable of being decolorized by exposure to light in a different An appearance characteristic of high-gloss surfaces where the highlights have a hazy border. portion of the spectrum or by BLUE [5] subsequent chemical action controlled by a photographic image. (1) The hue visual sensation BLIND SPOT (OPTIC DISC) [5] An irregular area in the retina which is not sensitive to light- stimulation because it lacks rods and cones. The exit point of the OPTIC NERVE. Note: The blind spot is around 6.5? of visual angle in diameter and is situated about 15? to the nasal side of the center of the retina, corresponding to the place of exit of the optic nerve. The blind spot explains the substantial gap in the temporal typically evoked by stimulation of the normal human eye with radiation of wavelength approx- imately 476 nanometers. (2) Any hue predominantly similar to that of the typical blue. (3) The COMPLEMENT of YELLOW. A rare type of partial color- blindness, in which blue and yellow stimuli are confused because the color gamut is side of the monocular visual space. reduced to reds, greens, and grays. Approved For Release 2003WJ t P -M 461304560A007300010028-8 Approved For Release 20e bWib l,WW P78BO456OA0073000199f@f -01/72 BLUE-YELLOW BLINDNESS (Continued) See Also: TETARTANOPIA BLURRY [5] Having uncertain outlines. BLURRED NEGATIVES [4] Any negative showing indistinct outlines of the image or double outlines is "blurred". This may be due to: (1) A poor lens, (2) Camera out of focus, (3) Camera motion, (4) Image motion, (5) Platen vacuum failure. BOSTROM TEST A defective color-vision test based on colored figures being perceived on a differently colored background. Not extensively used or known. BOUGER'S LAW [6] (1) Stated formally: for a molecularly dispersed colorant of a given concentration, the transmitted flux (It) of single- frequency light of wavelength A is a function of the incident flux (Io), the EXTINCTION COEFFI- CIENT (aA) and the thickness (1) of the medium: I = I e.a X1 t 0 (2) A mathematical expression relating transmittance of a single wavelength through a colored medium to the INCIDENT FLUX, EXTINCTION COEFFICIENT, and thick- ness of the medium. More simply, equal layers of a transparent material absorb equal fractions of each kind of energy entering them. (3) Also known as LAMBERT'S LAW, but not the same as LAMBERT'S COSINE LAW. BRIGHT [5] BRILLIANT, lively in appearance, opposite of dull. Characterized by a relatively high degree of BRIGHTNESS. BRIGHTNESS [5] (1) Brightness is the LUMINOUS INTENSITY of any surface in a given direction per unit of projected area of the surface as viewed from that direction. B = dI6/dA cos 6 where I = Intensity, A - Area, and 6 is the angle between the direction of observation and the normal to the surface. (2) In common usage, the term brightness usually refers to the INTENSITY of sensation which results from viewing surfaces or space from which light comes to the eye. This sensation is determined in part by the definitely measurable "bright- ness" defined above and in part by conditions of observation, such as the state of adaptation of the eye. Approved For Release 20ffi IFIL 78BO456OA007300010028-8 Approved For Release 20031 /,1A~ b ilA flVC8BO456OA0073000109 Z8/R-01 /72 BRIGHTNESS (Continued) BRIGHTNESS RANGE [8] Term indicating the ratio of the BRILLIANCE of the extreme high- lights to the darkest shadows of a scene or image. brightness of a surface generally BRIGHTNESS RATIO [5] Note: In the defining equation above, A is the angle between the direction of observation and the normal to the surface. In prac- tice, few surfaces follow exactly the Lambert's Cosine Law of emission or reflection; hence, the is not uniform but varies with the angle at which it is viewed. Brightness can be measured not only for sources and illuminated surfaces, but also for virtual surfaces such as the sky. The ratio of the brightnesses of any two surfaces. When the two surfaces are adjacent, the brightness ratio is commonly called the BRIGHTNESS CONTRAST. The perceptual phenomenon in which BRIGHTNESS THRESHOLD, ABSOLUTE an object appears to have the same brightness under various levels The minimum LUMINANCE level of of illumination. , a stimulus (with a particular A BRIGHTNESS difference between a visual area and its surrounding. The greater the difference, the higher the contrast. Note: The equation is LIo-LIb LIb where LI = Luminous Intensity, o = object, and b = Background. See Also: BRIGHTNESS RATIO BRIGHTNESS PURITY See LUMINANCE PURITY SPECTRAL DISTRIBUTION) required for the stimulus to be seen. The value is determined after complete DARK ADAPTATION but does not exclude the effect of processes normally active in the sense organ. Note: The absolute Brightness Threshold under optimal condi- tions is about .001 to .005 foot- lambert for FOVEAL CONES and .000001 foot-lambert for RODS 161. BRIGHTNESS THRESHOLD, DIFFERENTIAL The JUST-NOTICEABLE DIFFERENCE between two brightness levels, or Bob where B = Brightness, o+Bb o = object and b = background. Approved For Release 2003TQ?'hW1DWdA-8B0456OA007300010028-8 Approved For Release 20Nhk fifflgP78B04560A00730001R$?PA-01/72 BRIGHTNESS THRESHOLD, DIFFERENTIAL BULK COLOR (Continued) Note: The Differential Brightness Threshold under optimal conditions BURNHAM-CLARK-MUNSELL COLOR MEMORY is about .02 to .05 over an TEST [6] extended range of luminance (about 1 to 1,000 foot-lamberts). Another name for LUMINOSITY, i.e., the intensity of light reflected from a surface (incident light intensity X reflectivity of surface)'. A short-term color memory test in which the subject looks at a color chip for 5 seconds, and then it is covered. Five seconds later the subject chooses from a group of 43 differently colored chips the one which matches the covered chip. 20 colors are tested. People are scored "Superior", "Normal", or "Low". The maximum brightness sensation occurring .05 to .2 seconds after the onset of a steady (state) light. BROWN A dark orange BRUNSWIK RATIO [11] A measure of COLOR CONSTANCY. A ratio which indicates the degree an object retains its color when viewing conditions are changed. Note: The ratio is expressed as S-S' where L = luminance of L-S' unshadowed area, S' = luminance of shadowed area, and S = luminance of the exper- imental match to the shadowed area. Approved For Release 20?f ")WP78B04560A007300010028-8 Approved For Release 2003eMAN@Ij (8BO456OA0073000100 8-8/R-01/72 CALLIER QUOTIENT [4] The ratio between DIFFUSE and SPECULAR DENSITY as measured on a given photographic emulsion (also called "Q-Factor"). Note: A low Q-factor means that light is being absorbed rather than being scattered by the emulsion. A high Q-factor means the opposite is occurring. CAMOUFLAGE'DETECTION FILM See COLOR INFRARED FILM CAMPIMETRY The measurement of the extent colors are perceived from the FOVEA. The test uses a Campimeter which is a flat chart for mapping the color sensitivity of the entire RETINA. CANDELA (Formerly CANDLE) [4] The international unit of LUMINOUS INTENSITY of a source of light; the luminous intensity, in the direction normal to a BLACKBODY surface of 1/600,000 sq. meter in area at the tem- perature of solidification of platinum under a pressure of 101,325 newton/meter2. Note: See Figure 4 in the Appendix. CANDLE [4] See CANDELA CANDLEPOWER [4] LUMINOUS INTENSITY expressed in terms of the CANDELA. Note: Use as "The Candlepower of the light source is 60 candelas". CARDINAL POINTS [4] In a thick lens system, the two PRINCIPAL POINTS, the two NODAL POINTS, and the two FOCAL POINTS. CARDINAL STIMULI [5] Four standard visual stimuli by means of which the three reference stimuli and the basic stimulus of any TRICHROMATIC system may be defined. For example, light of wavelengths 700, 546.1 and 435.8 nm and Illuminant B have been used by the CIE. Note: Any three-color system should have red, blue, and green stimuli plus an illuminant. Cardinal stimuli are simply those colors and the illuminant chosen. See Also: CIE COLOR SYSTEM; CIE SOURCES; TRICHROMATIC COLOR SYSTEMS. Approved For Release 200t7MRlC@N- 78BO456OA007300010028-8 Approved For Release 2003/0 5J~~~ P7860456OA0073000 "01/72 CEILING The height above the earth's surface of the lowest layer of clouds or obstruction phenomena that is reported as "broken", "over- cast", or "obscuration" and not classified as "thin" or "partial". Note: Preferably, color should be acquired when there is no ceiling (full sun) and must be acquired below ceiling. CELSIUS (?C) Formerly known as Centigrade. A temperature scale in which the freezing point of water is labelled 0? and the boiling point 1000. A measure of length; 1/100 of a meter; abb.: cm CENTIGRADE (?C.) Now known as CELSIUS. CHARACTERISTIC CURVE (H AND D CURVE; SENSITOMETRIC CURVE; D LOG E CURVE) A curve showing the relationship between exposure and resulting density in a photographic image, usually plotted as the optical density D [D = log (1/T) (T-Transmittance or amount of light passing through an area divided by the total amount of light striking the area) or degree of blackening of an exposed film] against the logarithm of the exposure (log E) in candela-meter- seconds. Note: In the Figure below is a set of Characteristic Curves for the three dye. layers of a color film where'A is the TOE; B is a STRAIGHT LINE portion, and C is called the SHOULDER. The Characteristic Curve is extremely important and from it can be obtained (in part) the ASA SPEED of the film, CONTRAST, EXPOSURE LATITUDE, D-MAX, D-MIN, and GAMMA. Log E CHEMICAL FOG [4] DENSITY produced on photographic paper or films by chemical means such as too energetic or contaminated DEVELOPER. The tissue layer, which contains many blood vessels to nourish the eye, that lies between the SCLERA (outer tissue of the eye) and the RETINA. Note: See Figure 1 in the APPENDIX. CHROMA (1) Synonomous with SATURATION (but also with COLOR). Approved For Release 20%Wp ME78BO456OA007300010028-8 Approved For Release 200 ( t 1tft L78B04560A00730001?1/R- 01/72 Note: In the Figure below, blue, green, and red wavelengths are (2) The dimension of the MUNSELL focused on different planes COLOR SYSTEM which corresponds most because of longitudinal chromatic closely to saturation. aberration. Note: The word CHROMA has been used in many ways. To avoid confusion it should only be used with reference to the Munsell Color System. Otherwise use the term "saturation". See Also: MUNSELL COLOR SYSTEM; SATURATION; VIVID. A binocular illusion of depth CHROMATIC COLOR [5] which occurs when viewing small, highly saturated targets or areas A color which has HUE and against homogeneous backgrounds of SATURATION. a widely separated wavelength, e.g., a red body against dark blue See Also:. ACHROMATIC COLOR (for water. The target will appear to comparison) stand out from the background even though it may have no height; if CHROMATIC CONTRAST it does have height, it will be exaggerated. Chromatic means having some perceptible degree of SATURATION and HUE. CHROMATIC ABERRATION [4] CHROMATIC DISCRIMINATION [18] Ability to distinguish CHROMATICITY differences. CHROMATIC FLICKER [5] A defect (unequal REFRACTION) in a lens which causes rays of light of different wavelengths to be brought to a focus at different points in the space. There are two types: LONGITUDINAL CHROMATIC ABERRATION and LATERAL CHROMATIC ABERRATION. A pulsating or flicker phenomenon caused by differences in HUE and SATURATION, either singularly or combined, that occurs between stimuli of equal LUMINANCE which are alternately applied to the same retinal area. Approved For Release 200 N11LDE b k8B04560A007300010028-8 Approved For Release 20p /QtlbtR f[lF P78B04560A00730001 8T?-01/72 CHROMATIC FLICKER [5] (.Continued) White Fluore- Note: Distinguished from flicker scent Lamp (4500 K) 0.359 0.363 in general which may involve pulsations in brightness. White Fluore- scent Lamp (3500 K) 0.404 0.396 CHROMATIC RESOLVING POWER See RESOLVING POWER, CHROMATIC CHROMATICITIES OF CIE STANDARD SOURCES [5] The chromaticities of the CIE standard for COLORIMETRY are: Source A x = 0.4476 y = 0.4075 Source B = 0.3485 0.3518 Source C = 0.3101 = 0.3163 Source D65 = 0.3127 = 0.3291 See Also: CIE SOURCES; DAYLIGHT D ILLUMINANTS (1) The quality of a color specified by DOMINANT WAVELENGTH (alternatively, COMPLEMENTARY WAVELENGTH for purples) and PURITY, taken together. (2) In the CIE system of color measurement, Chromaticity is expressed mathematically by two numbers, x and y, termed CHROMATICITY COORDINATES; a diagram showing the ranges of these coordinates for all colors is termed a CHROMATICITY DIAGRAM. CHROMATICITIES OF OTHER IMPORTANT SOURCES AND ILLUMINANTS [5] The approximate chromaticities of various sources and illuminants are indicated by the following CHROMATICITY COORDINATES: Sunlight x = 0.336 y = 0.350 Average Daylight 0.313 0.328 North Sky Light 0.277 0.293 Zenith Sky 0.263 0.278 White Flame Carbon Arc 0.315 0.332 Daylight Fluore- scent Lamp (6500 K) 0.313 0.329 Note: CHROMATICITY is equivalent to the common concept of quality as distinguished from quantity of light. In the CIE system, they are the ratios of each of the three TRISTIMULUS VALUES (X, Y, and Z) of a sample color to the sum of the tristimulus values: X , X + Y + Z Approved For Release 20(M$BlofM4AIP78BO456OA007300010028-8 Approved For Release 2OO 1f 1DlN-78B04560A00730001OM-B/R-01/72 CHROMATICITY COORDINATES (Continued) They are the coordinates for the CIE COLOR DIFFERENCE FORMULAS AND CHROMATICITY DIAGRAM; See Figure 2 UNITS in the Appendix. See COLOR DIFFERENCE FORMULAS AND CHROMATICITY DIAGRAM UNITS A plane diagram formed by plotting CIE COLOR MATCHING FUNCTIONS one of any set of three chromaticity coordinates against See COLOR MATCHING FUNCTIONS another. CIE COLOR SYSTEM Note: See Figure 2 in the Appendix for an example of the Diagram. CHROMATOPSIA [5] An abnormal state of vision in which colorless objects appear colored. For example, yellow after santonin, red after snow- blindness. Dye formed as a result of the chemical reaction between the oxidized COLOR DEVELOPER (the exhausted form remaining after the DEVELOPMENT of image silver) and the DYE COUPLER. CHROMOSCOPE [5] A type of colorimeter using color produced by the rotary dispersion of quartz as standards. Somewhat out-of-date. Abbreviation for Commission Internationale de 1'Eclairage, the French title of the International Commission on Illumination. The CIE Color System is a color designating system based on the physical aspects of light and color perception. Note: This system is too complex to fully describe here. The reader is referred to references [1], [6], and [17]. CIE DISTRIBUTION COEFFICIENTS See DISTRIBUTION COEFFICIENTS CIE ILLUMINANTS (CIE STANDARD ILLUMINANTS) Spectral power distributions defining standard illuminants for colorimetric calculations. Included are the spectral power distributions of CIE SOURCES A, B, C and the spectral power distributions defining the CIE Daylight D illuminants. See Also: DAYLIGHT D ILLUMINANTS CIE PURITY See PURITY Approved For Release 2003 1 PIM.81304560A007300010028-8 Approved For Release 20effllbEl 1ffP78B04560A00730001i$ O /a-01/72 CIE SOURCES (CIE STANDARD SOURCES) ICI standards or (in Germany) IBK standards. Source A: A gas-filled incandescent lamp operating at CIE TRISTIMULUS VALUES 2854 K. Source B: Same as above, but with a filter to produce an CILIARY BODY approximation to noon sunlight. (COLOR TEMPERATURE of 4870 K). Source C: Same as A, but with a filter to produce an approximation to overcast skylight. (Color temperature of 6740 K). Note: See Figure below: p. 1 Wavelength, nm A body of tissue which contains three groups of muscle fibers to change the shape of the LENS of the eye during focusing. Note: See Figure 1 in the Appendix. CINCHING [4] Tightening a roll of film by holding the spool and pulling the free end; frequently results in parallel scratches or abrasion marks. CIRCLE OF CONFUSION (CIRCLE OF LEAST CONFUSION) 14] The circular image of a distant point object as formed in a focal plane by a lens. A distant point object (e.g., a star) is imaged in a focal plane of a lens as a circle of finite size because of lens aberrations. . See Also: CHROMATICITIES OF CIE STANDARD SOURCES; DAYLIGHT D ILLUMINANTS Standards of illuminants and of color perception set up by the Commission Internationale de l'Eclairage (International Commission of Illumination) to provide a means of accurately describing colors. Also known as CLARITY OF COLOR 15] Clarity of color means clearness of color in contrast to muddiness. CLEAN (CLEAR) [5] Free from a tendency to be dull, dingy, gray, dusty, or CLOUDY in appearance. Approved For Release 20 W EK78BO456OA007300010028-8 Approved For Release 200 Q5j iaA-178BO456OA00730001098/R-01/72 CLOUDY [5] Blotchy, uneven color of "milky" appearance. COATED LENS [4] A lens whose surfaces have been coated with a transparent film of such thickness and index of refraction as to minimize the light loss due to reflection. See Also: ANTI-REFLECTION COATINGS COLLIMATING LENS (COLLIMATION OPTICS) [4] A lens or optics which makes convergent or divergent rays parallel. (1) The process of making light rays parallel. (2) The process of aligning the OPTICAL AXES of optical systems. COLOR [4] (1) A general term for the quality of light distinguishable by the visual sense, e.g., black, white, gray, light blue, red, dark yellow, etc. (2) That property of an object which is dependent on the wavelength composition of the light it reflects, emits, and transmits. See Also: CHROMATIC COLOR; ACHRO- MATIC COLOR; METALLIC COLOR The ability to work with colors, e.g., color naming, color matching, color discrimination, and a good color memory. This aptitude can be improved with practice and experience with colors. A collection of color samples usually used for visual matching. COLOR BALANCE [4] (1) The relative adjustment of the overall intensities of the ADDITIVE or SUBTRACTIVE PRIMARIES in a color reproduction in order to give the best reproduction. (2) The proper intensities of colors in a color reproduction which, when balanced, give a correct reproduction of the gray scale. Note: Color balancing is a complex processing problem. Lack of proper balancing may result in imagery having a bluish, reddish, yellowish, etc., appearance. However, it should be noted that the reverse is not always true, i.e., yellowish imagery is not necessarily due to improper color balancing. Color vision defect marked by a partial (DICHROMATIC VISION; ANOMALOUS TRICHROMATIC VISION) or a total loss of color vision (MONOCHROMATIC VISION). Approved For Release 200 ON IfN-TZ48B04560A007300010028-8 Approved For Release 2 O E I rHQP78604560A00730001 9 8r~_01/72 The photographic image on a negative may be pure black or it may be colored. If the color is non-actinic with respect to the printing paper used, the print obtained will have more contrast than one from an untinted, but otherwise identical, negative. The ratio of the GAMMA of the colored negative, as determined from the print made from it, to the gamma of an otherwise identical negative is termed the Color-Coefficient, or the Color- Coefficient of contrast. COLOR, CLASSES OF [5] Colors may be divided generally into two distinct classes, CHROMATIC and ACHROMATIC. Colors generally do not appear to change with varying illumination levels or types even though the wavelength composition may have changed. Note: A U. S. Army vehicle that is partially shaded may appear to have the same continuous olive- drab color when, in fact, the shaded portion is a darker color. See Also: BRUNSWIK RATIO; THOULESS RATIO COLOR CONTRAST See CONTRAST, COLOR COLOR CONVERSION [18] Change in any dimension of ACHROMATIC COLORS vary only in perceived color due to change in BRIGHTNESS. CHROMATIC COLORS vary any conditions of viewing. in BRIGHTNESS, HUE, and SATURATION. COLOR CO-ORDINATE TRANSFORMATION [7] See Also: METALLIC COLORS COLOR COMPARATOR An instrument designed for the comparison of colors. Computation of TRISTIMULUS VALUES of colors in terms of one set of PRIMARIES from the tristimulus values of the same colors in terms of a different set of primaries. Note: The widest use of color comparators is the determination of the concentration of a known constituent in a solution; such instruments are sometimes called Chemical Colorimeters. COLOR COUPLERS (DYE COUPLERS) Chemicals that form dyes in the emulsion by reacting with the oxidized products formed during DEVELOPMENT. The amount of dye in any one place is proportional to the exposure in that layer of the color film. Approved For Release 20M fIN)[ MLP78BO456OA007300010028-8 Approved For Release 200 M'ib A I78B04560A007300010U$-O/R-01/72 VISION, DICHROMATIC VISION, and ANOMALOUS TRICHROMATIC VISION. A term usually applied to lenses or optical systems to refer to their COLOR DENSITOMETER designs which insure that they minimally alter or imbalance the wavelengths of light passing through. Note: For example, lenses which focus red at a different plane than blue are not Color Corrected. Color imagery and panchromatic films (sensitive to a wide range of wavelengths) must be acquired with Color Corrected optical systems. COLOR CORRECTION FACTOR (to a photometer) The factor by which the readings of a PHOTOMETER must be multiplied in order to obtain values in conformity with the VX function for light of a spectral composition different from that by which the photometer was calibrated. A device which measures the RADIANT FLUX for three bands of wavelengths (red, blue, green) by using three filters whose peak absorption wavelengths are at or near the absorption peaks of the three colorants used in the color reproduction being measured. The measurement of dye densities in color reproductions. There are two major types of measurements: ANALYTICAL DENSITOMETRY and INTEGRAL DENSITOMETRY. COLOR DEVELOPER [5] A chemical substance or mixture of substances capable of reducing silver halides with the simultaneous production of an insoluble colored product (a DYE) in regions of the silver deposit. Mathematical formulas used to express numerically the perceptual COLOR FIDELITY difference between two colors. Note: There are many different formulas, all which disagree with one another and none of which agree perfectly with visual perception. A general term for all forms of color vision different from normal. Includes MONOCHROMATIC A term generally applied to the degree that colors on an image match those of the original scene. Note: No known color film has perfect color fidelity although fidelity is quite good when acquired properly. Color Fidelity is severely affected by atmospheric attenuation and improper exposure settings. Approved For Release 2003/Cft F WE1 T4 kB04560A007300010028-8 Approved For Release 200dff16tk4# REP78BO456OA0073000 ,8 -01/72 A compound added to the emulsion layer which reacts with the oxidized COLOR DEVELOPER to form specifically colored dyes, e.g., YELLOW DYE, MAGENTA DYE, and CYAN DYE. The range of colors produced by a given method. COLOR INFRARED (IR) FILM A Kodak false-color film (Ektachrome Infrared 8443) which is also known as Camouflage Detection film. The emulsion layers are sensitive to green, red, and infrared wavelengths. Living vegetation emits infrared wavelengths and appears red on the film and dead vegetation appears yellowish/ brownish on the film. Thus, dead vegetation used as camouflaging materials can be distinguished from living vegetation. COLOR INTERVAL [5] The degree of visual difference between two colors measured in steps of HUE, VALUE, and CHROMA. Any two visual sensations which appear to be the same in terms of color. The procedure of determining whether two visual sensations are the same in terms of color. Color matching is usually done with a sample color and a set of reference colors. One attempts to select one of the reference colors which has the same (or nearly the same) color as the sample color. Note: Color matching should be done with the same type and intensity of illuminant and the eyes must be LIGHT-ADAPTED. See Also: VISUAL COLORIMETRY, INSTRUMENTAL COLORIMETRY In the CIE color system they are designated as x, y, and z and represent the color matching pro- perties of a standard observer. Note: See Figure below for the distributions. 500 600 Wavelength, nm Approved For Release 20( ,FH)EWP78BO456OA007300010028-8 Approved For Release 2003{ f I rTFp78BO456OA007300010VPI~/R-o1/72 11 COLOR MATCHING FUNCTIONS (Continued) COLOR PHOTOGRAPHY [4] See Also: STANDARD OBSERVER The reproduction of subject or scenic matter in natural colors by COLOR MIXTURE photography. The combination of two or more COLOR POSITIVE FILM colors. A photographic film whose colors COLOR-MIXTURE DATA after DEVELOPMENT are nearly the same as the original (1) The amounts of red, blue, and scene. green light needed to be combined to perceive a particular color. COLOR PYRAMID and green) to establish a color COLOR RENDERING match with a sample color. (2) The'amounts of the colorimetric primaries (red, blue, A photographic film whose colors after DEVELOPMENT are COMPLEMENTS of the original scene. COLOR NORMAL A person with normal color vision. See NORMAL TRICHROMATIC VISION COLOR NOTATION Symbols arranged in some orderly fashion by which the attributes of color may be communicated either verbally or written. For example, in the MUNSELL COLOR SYSTEM the Color Notation 5Y 4/10 is used to communicate a particular yellow color. The visual experience of color. The effect a light source has on the appearance of colors compared to the effect produced with a standard or reference light source. A measure of the degree to which the perceived colors of a set of test objects illuminated by a source as compared to their per- ceived colors when illuminated by a standard source under specified conditions. The index ranges from 0 to 100. An index of 100 means that the source affects the appearance of color the same as the standard. An index of 50 is an example of the shift from fluorescent light to incandescent light. Note: The basic problem with this index is understanding what the Approved For Release 200 NEIDUEI Ph8BO456OA007300010028-8 Approved For Release 20p /Q5-L'I6t fifrF QP78BO456OA00730001 ? 7?-01/72 COLOR RENDERING INDEX (Continued) numbers mean in terms of perceived colors. For example, how the colors are perceived when illu- minated by a source with an index of 83 is difficult to determine. COLOR REVERSAL FILM See REVERSAL FILMS, COLOR COLOR SCALE [5] An orderly arrangement of colors showing graduated change in HUE, SATURATION, or BRIGHTNESS. COLOR SENSATION [5] Any visual experience of a CHROMATIC nature which results from stimulation of the retina, as distinguished from the physical considerations descriptive of the stimulus. The variations in brightness or lightness of a color, e.g., light red, dark red. COLOR SOLID [5] A symbolic figure in three dimensions which represents the relations of all possible colors with respect to their primary attributes of hue, brightness or lightness, and saturation. Usually brightness (lightness) appears as the vertical axis of the figure, with hue and saturation represented in polar coordinates about the brightness axis, and saturation being radial. The boundaries of the solid are actually irregular, but it is sometimes represented as a cylinder, a sphere, a spindle, a double cone or a double pyramid with a common (square or triangular) base. COLOR SPECIFICATION [5] A description of a color made in The sensitivity of a photographic such a way that the color emulsion or the retina of the eye sensation may be duplicated. This to light of various wavelengths. may be done with the aid of certain visual color matching devices, such as COLORIMETERS or COLOR COMPARATORS. The separate photographic records (usually 3 panchromatic negatives) See Also: COLOR NOTATION of the relative intensities of the primary colors (reds, greens, or COLOR STANDARD blues) in a scene or color image (transparency or print). See Also: ADDITIVE COLOR SEPARATIONS A color whose dimensions of HUE, SATURATION, and BRIGHTNESS have been accurately measured and specified and then used for comparison purposes. Approved For Release 206iDUF''1VE4;-Ik,P78B04560A007300010028-8 Approved For Release 2003/ee(W:I b A18B04560A0073000100 f /R_o 1 /72 COLOR STANDARD (Continued) Note: Munsell chips are in a sense Color Standards when they are used to determine the name or designation of other colors. COLOR STIMULUS [5] (1) RADIANT ENERGY of any luminance and wavelength composition within the ranges which are capable of adequate stimulation of retinal receptors. (2) The term is sometimes limited to adequate stimuli for evoking the sensation of HUE. COLOR SURFACE [5] A plane section of a COLOR SOLID (usually taken perpendicular to the axis of brightness variation) that represents all possible hues and saturations at a single brightness level. The temperature (in Kelvin) of a ]3LACKBODY radiator whose SPECTRAL DISTRIBUTION matches that of the color being designated. Note: The blackbody colors form a single series of relatively unsaturated visual qualities, ranging from red, through orange, white, pale blues, and violets as the temperature is increased. For example, if a light source has a SPECTRAL DISTRIBUTION which matches that of a blackbody at 3,000 Kelvin, then the light source is said to have a Color Temperature of 3,000 Kelvin. See Also: CORRELATED COLOR TEMPERATURE; RECIPROCAL COLOR TEMPERATURE; BLACKBODY; MIREDS The luminance below which color becomes no longer discernible. The level varies for different colors, but minimum is about 103 candelas/square meter at which red is first perceived. COLOR TRANSPARENCY [5] A color photograph upon a glass or film support to be viewed or projected by transmitted light, as distinguished from a color photograph on paper or other opaque white support to be viewed by reflected light. COLOR TRIANGLE [5] A diagram (typically) in the form of an equilateral triangle with apices representing red, green, and blue primaries and the enclosed area representing all the CHROMATICITIES possible by additive mixture of these three primaries. Note: Characteristic of the color triangle is the adjustment of the primary scales so unit amounts will yield an achromatic mixture which is represented by the centroid of the triangle; and the relative amounts of the primaries necessary to yield each chromaticity are then indicated by corresponding distances on the triangle. See Also: COLOR SOLID; CHROMATICITY DIAGRAM; MAXWELL TRIANGLE Approved For Release 200 NEI: ElPIz8B0456OA007300010028-8 Approved For Release 20e ffll fEA ..EP78BO456OA00730001t iL-01/72 COLOR VISION [5] Vision with the response of CHROMATIC COLORS. See Table 2 in the Appendix for brief descriptions. Individual theories listed in Table 2 may also be found in the Glossary. COLOR WEAKNESS [5] A defect in color vision marked by diminished color sensitivity rather than actual loss of sensitivity to any HUE. See Also: ANOMALOUS TRICHROMATIC VISION COLOR ZONES (COLOR FIELDS) [5] Regions of the retina which have different characteristics as to chromatic color response. Note: For most individuals and usual conditions, the central region shows full chromatic color response, while red and green responses disappear at a moderately peripheral position and blue and yellow fail toward the extreme periphery. The exact size boundaries of any zone depend upon the size, intensity, and saturation of the stimulus used; they also vary with the individual and with the measurement technique employed. See Also: CAMPIMETRY; PERIMETRY. A DYE or PIGMENT which selectively absorbs particular wavelengths. COLORED SHADOW PHENOMENON [5] An accentuated type of SIMULTANEOUS COLOR CONTRAST observed when two shadows are cast upon the same surface near each other by two lights of different color; when the shadows are made about equal in brightness, each one tends to appear of a color COMPLEMENTARY to that of the light which casts it. COLORIMETER [5] A color measuring instrument for comparing a known color to an unknown color so that the latter is specified in terms of the former. The colorimeter may be calibrated or the specification may be transformed to yield a measurement in terms of some standard system of colorimetry. Note: Generally, the instrument is used to determine approximate CIE Tristimulus values X, Y, and Z for a transparent or opaque sample. See Also: SPECTROPHOTOMETER: TRISTIMULUS COLORIMETER The science of measuring color and expressing colors numerically. The measurements can be made visually or with devices. Approved For Release 20Gf)1HDEN l P78BO456OA007300010028-8 Approved For Release 20031e9bw:I6g18B04560A0073000100$$C/R-01/72 COLORIMETRY (Continued) See Also: VISUAL COLORIMETRY; INSTRUMENTAL COLORIMETRY Density measurements on color films (using the STANDARD OBSERVER) used to determine how the colors will appear to the standard observer. A lens aberration affecting the sharpness of images off the OPTICAL AXIS which causes oblique light rays from a point source to be imaged as a comet-shaped blur. Thus objects will appear out-of- focus. COMPARISON LAMP [5] A Comparison Lamp is a lamp of constant but not necessarily known candlepower against which standard A PHOTOMETER designed to measure and test lamps are successively the intensity of light of different compared in a PHOTOMETER. colors through the use of filters COLORIMETRIC PHOTOMETER [4] interposed in the path of the light. COLORIMETRIC PRIMARIES [5] Any three colors which are additively mixed to match an unknown color when making a colorimetric measurement. Representative red, green, and blue stimuli are most commonly used as Colorimetric Primaries; but theoretically any three colors can be used if the color of any one cannot be matched by mixing the other two. COLORIMETRIC PURITY [5] EXCITATION PURITY multiplied by the ratio of the luminances of the spectrum color and the sample color. Note: In the case of purples, the calculation is made using the spectrum color corresponding to the COMPLEMENTARY WAVELENGTH of the sample color. One of a pair of colors (from light sources) which when mixed produces a neutral gray, white, or black. One of a pair of COMPLEMENTARY COLORS. Note: Red is the Complement of Blue-Green; Green is the Complement of Blue-Red; Blue is the Complement of Yellow; and vice versa. COMPLEMENTARY COLORS (COMPLEMENTS) [7] ,Two colors (from light sources) which when combined in the proper amounts mix to produce an ACHROMATIC COLOR. Note: Complementary Colors are red -- blue-green (CYAN), green -- red-blue (MAGENTA), blue-- (YELLOW). Approved For Release 2003/MFM)EtkbBO456OA007300010028-8 16E Lftl~P78BO456OA00730001 8t?-01/72 Approved For Release 20effl 051 COMPLEMENTARY WAVELENGTH(S) The wavelength(s) of light which when combined in suitable propor- tions with another color and matches an adopted ACHROMATIC COLOR is the Complementary Wavelength of the other color. the center of the retina (FOVEA) the cones are long and slender and closely packed to the exclusion of rods and farther out they are shorter and thicker and interspersed among the more numerous rods. It is estimated that there are 7,000,000 Cones in the human retina. Note: The wide variety of purples (including nonspectral violet, CONDITIONAL MATCH purple, magenta, and nonspectral red colors) which have no DOMINANT WAVELENGTHS are specified by use of their Complementary Wavelengths in the CIE COLOR SYSTEM. COMPLETE DIFFUSION [5] A match between two colors which is agreed upon by most observers under most light sources. The tendency of colors to attract Complete diffusion results when a attention, particularly on color diffusing medium scatters the transparencies. light upon it so completely that none is regularly reflected or Note: The term is derived from transmitted, and objects from the word "conspicuous" which means which the light originally came standing out from the background cannot be distinguished. and immediately noticeable. CONE, RETINAL [5] CONSTANCY A type of minute structure found See COLOR CONSTANCY; BRIGHTNESS in the retina of the eye which CONSTANCY constitutes a specific receptor for color vision. Distinguished CONTACT PRINT [4] from retinal RODS, another visual receptor; the cones are without A print made by placing a negative visual purple (the chemical in contact with sensitive paper Rhodopsia) and are believed to while exposure is being made. operate for both CHROMATIC and ACHROMATIC (gray) visual qualities CONTINUOUS SPECTRAL DISTRIBUTION at higher levels of illuminations; the rods for achromatic only at A SPECTRAL DISTRIBUTION that is low (twilight) levels. Currently, never zero over a considerable there are thought to be three types spectral range. of cones sensitive to red, blue, or green. The rods and cones form See Also: SPECTRAL DISTRIBUTION the 2nd layer of the retina (from the surface of the eyeball). At Approved For Release 20 M 78BO456OA007300010028-8 Approved For Release 2003/t"Fige B0456OA0073000100248C/R-01/72 CONTINUOUS SPECTRUM [5] A SPECTRUM or section of a spectrum in which radiations of all wavelengths are present. CONTRAST [4] In photography the difference between highlights and shadows. The ratio of reflecting power between the highlights and shadows of a print determines the contrast. Contrast in a transparency is determined by the ratio of the DENSITIES of the parts compared. CONTRAST, COLOR [5] (1) The ratio of the intensities of the sensations caused by two colors. Sometimes the logarithm of this ratio. (2) Also used for SIMULTANEOUS COLOR CONTRAST Note: High color contrast means that there is a large difference between the two intensities of two colors, e.g., yellow vs. black; whereas low color contrast means a small difference between the two intensities, e.g., pink vs. red. CONTRAST FACTORS [4] The amount of contrast in a finished photograph may be attributed to several factors. They include the exposure, the filter used, the type of film, the duration of negative development, the duration of exposure and development in printing, and the paper used in printing. CONTRAST FILTER [4] A color filter chosen to make a colored subject stand out very sharply from surrounding objects. CONTRAST TRANSFER FUNCTION See MODULATION TRANSFER FUNCTION CONVERGENCE The turning of the eyes inward as objects are brought close. COOL COLORS [5] Colors of green or blue or colors containing a marked predominance of green or blue. The transparent area at the front of the eye and directly in front of the pupil and lens. Note: See Figure 1 in the Appendix. CORRECTION FILTER [8] Term for any filter which alters colors to suit the color response of the film in use. Any color filter can be regarded as a correction filter. Approved For Release 2003 A57 F:IPFA'-14i 8B04560A007300010028-8 Approved For Release 20WEIBERI AQP78BO456OA0073000'O8MB-01/72 The color temperature of the blackbody whose CHROMATICITY is nearest that of the source considered. Used when the spectral power distribution of the source does not match that of any blackbody, even approximately. For example, the chromaticity of noon summer sunlight is closer to that of the blackbody radiator whose color temperature is 5740 K. CRITICAL ANGLE [12] The angle beyond which total INTERNAL REFLECTION of a ray takes place when passing from a medium of higher index to a medium of lower index. The angle is expressed by the equation sine A = N'/N, in which A is the critical angle, N' is the lower index of refraction, and N is the higher index of refraction. Thus the correlated color CRYSTALLINE LENS temperature of noon summer sunlight is 5740,x, but the spectral power distributions of noon summer sunlight and a 5740 K blackbody are quite different. Note: Fluorescent lights (as in light tables) have spectral distributions which do not match those of BLACKBODY radiators and thus have Correlated Color Temperatures. COUPLER . See COLOR COUPLER COVERAGE, ANGLE OF See ANGLE OF COVERAGE CRAB [4] The condition caused by failure to orient the OPTICAL AXIS with respect to the track of the platform. In vertical photography, crab is indicated by the edges of the photographs not being parallel to the air-base lines. The LENS of the aye lying directly behind the AQUEOUS HUMOR; the shape of which is changed by the CILIARY BODY in order to focus the visual image onto the retina. Note: See Figure 1 in the Appendix. Features of the terrain that have been constructed by man. Included are such items as roads, buildings, and canals; boundary lines; and, in a broad sense, all items desig- nated by names and legends on a map. A lens aberration which causes a flat object surface to be focused as a curved image surface. All good optical systems are corrected for this aberration. Note: See Figure below. On imagery this aberration results in only the outer portions of the scene being out-of-focus. Approved For Release 20 ALP I* 78BO456OA007300010028-8 Approved For Release 200t'11 1fgDE114llf78BO456OA007300010@TZWR-01/72 CURVATURE OF FIELD (Continued) A curve showing the variation of LUMINOUS INTENSITY of a light source with the angle of emission. CUTOFF FILTERS See FILTER CYAN [5] The name applied to the blue- green colors or the wavelength of approximately 494 nanometers. Cyan is the hue COMPLEMENTARY to red. During the processing of color film, it is the blue-green dye formed in the red sensitive layer. Note: In positive transparencies it is formed where red wavelengths were not imaged, thus stopping the transmission of red except where it was imaged. In negatives it is formed where red wavelengths were imaged, thus allowing its complement (CYAN) to be transmitted. See Also: YELLOW DYE; MAGENTA DYE CYANINE (CYANIN) Earliest known member of the class of cyanine dyes, a very large number of which have now been synthesized. The great majority of dyes used for sensitizing emulsions are of the cyanine class. Approved For Release 2003/95/16&UN8BO456OA007300010028-8 Approved For Release 20E0CfW1BEN AQP78B04560A0073000 8-01/72 D-LOG E See CHARACTERISTIC CURVE D-MAX [4] The highest density which can be obtained using a particular photo- graphic material. When referring to a particular negative or positive, the highest density recorded. Note: On the CHARACTERISTIC CURVE it is the highest density. D-MIN. [4] The lowest density on a positive or negative. Note: On the CHARACTERISTIC CURVE it is the minimum density. DALTONISM [5] Named for John Dalton, 1766- 1844, who was himself color-blind for red and green and published a description of his case. (1) Having the appearance of reflecting only a limited amount of light (tending toward BLACK). (2) Dark colors are those of relatively low BRIGHTNESS or LIGHTNESS. DARK ADAPTATION (DARKNESS ADAPTATION) An eye whose condition has been so modified by the withdrawal of general light that its sensitivity to light has increased. See Also: ADAPTATION, DARK DARKROOM [4] A room made free from light in which photographic operations are conducted. It is sometimes illuminated with a SAFELIGHT the rays of which are non-ACTINIC to the film or paper. DATUM [4] Refers to a direction, level, or position from which angles, heights, depths, speeds, or distances are conventionally measured. A special condition, usually due to impairment of the central area of the RETINA, in which the individual sees better in dim light. The total visible RADIATION from the sky and sun. Approved For Release 200KFlW dMdP78BO456OA007300010028-8 Approved For Release 2003tIf$16 AL8BO456OA007300010028 /R-01/72 DAYLIGHT (Continued) D normal trichromatism and complete dichromatism), and MONOCHROMATIC Note: Its SPECTRAL POWER VISION. DISTRIBUTION is shown in Figure 3 of the Appendix. DEFINITION [2] See Also: SKYLIGHT; SUNLIGHT. Degree of clarity and sharpness of an image. DAYLIGHT D ILLUMINANTS A series of CIE standard illuminants whose spectral power distributions are those of average daylight. CORRELATED COLOR TEMPERATURE is the variable within the series. The most important Note: A high degree of definition means that edges and details are sharp and colors are clear; implying high resolution, focus and good color fidelity, and balance. daylight D illuminant is D65, with DEGRADED COLOR a correlated color temperature of 6500 K. Next in importance are D55 and D75, with correlated color temperatures of 5500 and 7500 K, respectively. Formulas are available for calculating the spectral power distribution of any D illuminant with correlated color temperature between 4000 and 20,000 K. It is anticipated that ultimately D65 will replace CIE standard illuminants B and C for colorimetric calculations. DEEP COLOR Colors which are highly saturated. DEFECTIVE COLOR VISION [5] The condition in which color discrimination is significantly reduced in comparison with that of the NORMAL TRICHROMAT. Note: The forms of defective color vision can be divided into three main groups - DICHROMATIC VISION, ANOMALOUS TRICHROMATIC VISION (all cases lying between Colors which do not appear true or correctly balanced. DENSE [4] A term applied to negatives or positives in which the silver deposit is heavier than normal due to overexposure or over- development. DENSITOMETER [4] A device used to measure the OPTICAL DENSITY of deposits in a photographic image. There are many varieties, but all are alike in providing a means for comparing the intensity of a standard light to that of an identical beam of light which has passed through the area to be measured. Comparison between the two may be visual or by photoelectric cells. For determining the density of an image on paper, a Reflection Densitometer is used. Approved For Release 20031 l F:I P N8BO456OA007300010028-8 Approved For Release 20e9W Wff1AQP78BO456OA00730001i@ ;$fit-01/72 A color measurement system based on the Munsell Color System where instead of determining a color by matching with Munsell Chips, the HUE, VALUE, and CHROMA are determined with a DENSITOMETER and a set of nomographs. Note: Since a densitometer is used, colors on transparencies can be determined and referred to the MUNSELL COLOR SYSTEM. The technique of measuring densities on photographic images. Can be carried out by transmitted light (e.g., on a transparency) or by reflected light (e.g., on a paper print). The instrument used f h Note: There are many different ways of measuring densities on color emulsions. See ANALYTICAL, SPECULAR, DIFFUSE, INTEGRAL DENSITIES. See Also: ABSORBANCE; OPTICAL DENSITY The term usually refers to the "rich" quality of highly saturated colors. DESATURATED COLORS (PALE COLORS) Colors in which the SATURATION is noticeably decreased as compared with a standard. or suc measurement is a DESATURATION (DESATURATE) [18] DENSITOMETER; the results may be used for plotting the Reduction in SATURATION. CHARACTERISTIC CURVE of the material concerned or for EXPOSURE DESENSITISERS (DESENSITISING) [11] determination. See Also: DENSITY; SENSITOMETRY; COLOR DENSITOMETRY (1) The quantity per unit volume, area, or length. (2) The degree of OPACITY as defined as log10 1 Transmittance or log10 I 1 Reflectance A desensitiser is a substance which when applied to a sensitive emulsion reduces its sensitivity to light. Most desensitisers destroy, or partially destroy, the LATENT IMAGE on an exposed film; those that do not are mostly dyes. These are of great value in permitting even the fastest and most color-sensitive films, after a short treatment in total darkness, to be developed in a comparatively bright yellow light. (3) In EMULSION, it is the amount of silver grains or color dye globules in a given area. Approved For Release 20 FEN/EWP78BO456OA007300010028-8 Approved For Release 2003/?e l9\yk78BO456OA00730001002U-BC/R-01/72 DETAIL [4] The smallest discernible differences (e.g., object edges or colors) which are clearly defined; good detail implies high resolution and good focus. DEUTERANOMALOUS VISION (DEUTERANOMALY; a DEUTAN) [5] DEVELOPER (Continued) See Also: COLOR DEVELOPER DEVELOPMENT [11] Development is the production of a visible image from the invisible or LATENT IMAGE formed on sensitive material by exposure to light. A form of ANOMALOUS TRICHROMATISM in which more green is required in DEVELOPMENT BY INSPECTION [4] a mixture of red and green to match a spectral yellow than in Development of negatives or the case of the NORMAL TRICHROMAT. prints using direct observation The relative spectral visual and depending on the operator's sensitivity does not differ judgment as to when development noticeably from the normal but it is complete. is less in the red to green region. Hue discrimination is poor in the DIAPOSITIVE [8] red to green region of the spectrum. Positive image on a transparent support intended for viewing by Note: In the population, it transmitted light, e.g., a affects about 4.8% of males and transparency. .39% of females [6]. DEUTERANOPIA (a DEUTERANOPE) Light entering the eyeball through Form of DICHROMATIC VISION in the SCLERA layer (outer coating). which green and purplish red stimuli are seen as grays. The DICHROIC [5] deuteranope sees only spectral hues of blue and yellow and colors Pertaining to the ability of mixed therefrom. some selectively absorbing substances to vary in color with Note: In the population it layer thickness or concentration. affects about 1.1% of males and .01% of the females [6]. DICHROIC FILTER [5] A solution which converts the exposed grains of silver halide to metallic silver, forming the negative image. (1) A semitransparent mirror which selectively reflects some wavelengths more than others and so transmits selectively. Approved For Release 2003/0' / F'CIk-Df4hBO456OA007300010028-8 Approved For Release 20e6 bEf4ttATP78BO456OA00730001I0D284-01/72 DICHROIC FILTER [5] (Continued) (2) A filter transmitting two narrow regions of the spectrum. A term applied to a material which selectively transmits and reflects light depending upon its wavelength. DICHROMATIC VISION (a DICHROMAT) A form of defective color vision in which only two regions of the visual spectrum can adequately be perceived. Note: In dichromatic vision the spectrum is seen as comprising only two regions of different HUE separated by a gray band. Dichromatic vision can be subdivided into three types: PROTANOPIA, DEUTERANOPIA, and TRITANOPIA. See Also: PROTANOPIA; DEUTERANOPIA; and TRITANOPIA. (1) See DICHROMATIC VISION (2) The property of varying in HUE either as the dye concentration is changed or as the thickness of the transmitting sample changes. The difference between two compared stimuli (e.g., two colors) which gives rise (statistically) to a perceived difference 50% of the times viewed. See Also: JUST-NOTICEABLE DIFFERENCE DIFFRACTION [4] A term used in optics to denote the deviation of rays of light when such rays pass by the edge of an opaque body (a nontransparent object). Note: As an example, DIFFRACTION causes the edges of shadows to appear blurred because the light rays passing the object are bent and spread. A device used to separate a beam of light into the SPECTRUM COLORS using the principle of DIFFRACTION. The device itself contains a series of fine grooves or wires which disperse incident light. The OPTICAL DENSITY measured when the incident light on the collection aperture of the DENSITOMETER is not highly COLLIMATED and the collection aperture subtends a large SOLID ANGLE. Note: Most densitometers measure diffuse density. Approved For Release 20&QNF40EKTM 78B04560A007300010028-8 Approved For Release 2003 f i lPRE8BO456OA00730001001S ft/R-01/72 DIFFUSED LIGHT [4] Light which does not reach the object from a single direction. Note: Sunlight which has been scattered by the atmosphere or clouds is an example of diffused light. Generally, as diffusion increases, shadow sharpness decreases. The change of the spatial distribution of a beam of radiation when it is deviated in many directions on arrival at a surface or in traversing a medium. DIFFUSION CIRCLE [5] A circle of color in an optical system caused by rays emanating from a point source which have not been brought into sharp focus because of. CHROMATIC ABERRATION. A diffusion circle is likely to show different hues at different distances from its center. DIN [4] Deutsche Industrie Norm, German Standards. The official German color system in which hue, saturation, and darkness (the opposite of lightness) are called FARBTON(T or F), SATTIGUNG(S), and DUNKELSTUFE(D), respectively. There exists a set of color chips, DIN COLOR SYSTEM (Continued) each with a set of 3 numbers, e.g., 3:1:6, which describe the hue, saturation, and darkness, respectively. System of stating emulsion speeds as laid down by the Deutsche Industrie Norm (German standards organization). DIOPTER [4] The unit of measure of the converging or diverging power of a lens. It is equal to the reciprocal of the focal length in meters. Color matching in a COLORIMETER for the purpose of numerical specification of color. DIRECT LIGHT [5] Direct light is visible energy falling straight from its source upon the eye or upon an object. DIRECT REFLECTION [5] Reflection of light without scatter. Approved For Release 2003/09Aki' iN-Rb'8BO456OA007300010028-8 Approved For Release 2ta(folbERFftReP78BO456OA0073000 #-01/72 DIRECTIONAL REFLECTANCE [7] The amount of light reflected from a surface in a specified direction compared to that reflected in the same direction from an ideal, nonabsorbing, perfectly diffusing surface placed in the same position and similarly illuminated. 'DISCRIMINATION ELLIPSES See: MacADAM ELLIPSES DISPERSION [4] The separation of a single ray of white light into a group of colored rays by a prism or other optical device. Note: A Rainbow is an example of dispersed light. DISTRIBUTION COEFFICIENTS (DISTRIBUTION FUNCTIONS) [5] (Continued) COORDINATES of the spectral components of an equal-energy spectrum. Denoted x, y, z, in the CIE system and defined in a table of figures which represents the characteristics of the STANDARD OBSERVER. See Also: COLOR MATCHING FUNCTIONS The absolute temperature (in Kelvin, K) of the BLACKBODY RADIATOR for which the SPECTRAL POWER DISTRIBUTION at every wavelength in the visible spectrum (-400 to 700 nm) which is approximately proportional to that of the source considered. DISPLACEMENT, ANGLES OF [5] DOMINANT COLOR The angles by which the respective eyes deviate from the direction A term used to describe the occupied in the primary position. principal color or tone in a The vertical displacement is the picture. angle of the eye upward or down- ward from the primary position; Note: The Dominant Color of a the lateral displacement is the jungle photograph is green. angle to right or left. DISTORTION [4] Any shift in the position of an image on a photograph which alters the perspective or spatial characteristics of the photograph. DISTRIBUTION COEFFICIENTS (DISTRIBUTION FUNCTIONS) [5] A vision theory stating that there exists a separate dominating receptor for the brightness aspect of vision with CHROMATIC distinctions introduced by other receptors modulating the response of the dominant receptor. Note: See Table 2 in the Appendix. Approved For Release 206i)UFIJD6(NIIMP78BO456OA007300010028-8 Approved For Release 2003f f$,6 I R18BO456OA007300010090*/R-01/72 (1) On the CIE chromaticity diagram, it is the intersection of the SPECTRUM LOCUS and the line drawn through the chromaticities of the illuminant and the sample color. (2) It is analogous to the concept of HUE. Note: In Figure 2 in the Appendix, line A intersects the Spectrum Locus at 530 nm, thus 530 run is the Dominant Wavelength of color N. DRAM [41 A unit of weight in the avoirdupois system, one-sixteenth part of an ounce or 27.34 grains. DUPLICITY THEORY (Continued) systems present in the retina, the ROD and the CONE systems, respectively; the rod-system is supposed to be responsible for vision at low or twilight illumination levels and to yield an achromatic color; the cone supposedly mediates daylight and completes color vision but is inactive under twilight conditions. Note: It is currently accepted as the major theory of vision. A type of PSEUDO-ISOCHROMATIC PLATE test of color vision where colored dot patterns lie on a background of colored dots. People with normal color vision will see the dot patterns correctly while those with defective color vision will not see Generally, Dull colors are the patterns correctly. desaturated and low in brightness. DYE DUNKELSTUFE(D) In the DIN COLOR SYSTEM, a logarithmic function of the color's relative lightness. (Ratio of luminous reflection of color to the luminous reflection of the optimal color having the same CHROMATICITY.) A complex chemical, whose molecules absorb particular wavelengths; used as a COLORANT or coloring agent. Note: In color films, dyes (CYAN, MAGENTA, and YELLOW) are created in the emulsion as a result of the DEVELOPING process. Note: Literally translated Dunkelstufe means "darkness DYE COUPLER degree". The doctrine that visual sensation rests upon two distinct receptor Approved For Release 2003k9tif WWlk8B04560A007300010028-8 Approved For Release 2?E f 'i1'JE fft)P78B04560A00730001QM 01/72 DYE DENSITY DYE SENSITIZERS (1) The logarithm to the base 10 Used to sensitize silver halide of the OPACITY of an area in a emulsions to certain desired finished dye image. portions of the spectrum. (2) The density of a dye deposit is the log10 1 or Transmittance log10 1 Reflectance DYE FORMATION See CHROMOGENIC DYE FORMATION DYE GLOBULES In a processed color positive or negative these are microscopic globs of dye which give the image its color. There are three colors, CYAN, MAGENTA, and YELLOW, and mixtures of these globs produce the entire range of colors. The globs are visible under high magnification. DYE IMPURITIES [5] Pertaining to the absorption of light by a dye in regions of the spectrum where the dye should transmit completely. Note: All dyes are impure to some degree and thus cause some colors to be unfaithfully produced in the image. DYE MORDANTING [5] In color photography, the treat- ment of a silver image so as to replace it in whole or in part with a substance having an affinity for dyes. Approved For Release 20 F1MD:EM-MP78BO456OA007300010028-8 Approved For Release 20031 Jl4 6 g18BO456OA0073000100 */R-01/72 EDGE FOG [4] Fog on film caused by leakage of light between the flanges of the spool on which it is wound. EFFECTIVE APERTURE See APERTURE, EFFECTIVE EFFECTIVE TRITANOPIA See SMALL AREA TRITANOPIA EFFICIENCY OF A SOURCE OF LIGHT [5] The efficiency of a source is the ratio of the total LUMINOUS FLUX to the total power input. In the case of an electric lamp it is expressed in lumens per watt. In the case of a source depending upon combustion it may be expressed in lumens per thermal unit consumed per unit of time. The form in which RADIANT ENERGY travels or is propagated. The name applied to all wavelengths of RADIANT ENERGY, e.g., LIGHT, radio, INFRARED, ULTRAVIOLET, X-rays, etc. An optical part constructed of a simple piece of optical material, e.g., a lens, prism, or mirror. EMISSION The release of RADIANT ENERGY. EMISSIVITY The ratio of the RADIANT EMITTANCE of a source to the radiant emittance of a BLACKBODY at the same temperature. EMITTANCE, SPECTRAL See SPECTRAL EMITTANCE EMMERT'S LAW [5] The perceived size of an AFTER- IMAGE is directly proportional to the distance from the observer to the plane upon which the after- image is projected. The sensitive coating on films, papers, and plates used in photo- graphy. It consists principally of a silver salt or salts sus- pended in gelatin. The emulsion may be sensitive to the whole visible spectrum (PANCHROMATIC, COLOR) or selected portions (INFRARED, ORTHOCHROMATIC). EMULSION BATCH NUMBER [4] A number placed on the label of film and paper packages which identifies the batch from which that particular film or paper was made. Approved For Release 200-f-*NFII $J t8B04560A007300010028-8 Approved For Release 20e31Q 1 EWf iWQP78BO4560AO073000lp 87 .01 /72 EMULSION BATCH NUMBER [4] (Continued) EQUAL ENERGY SOURCE [5] Note: Variations in film characteristics can be expected between batches. EMULSION SPEED [4] A light source from which the amount of energy radiated is constant for the same wavelength interval throughout the visible spectrum. A property of photographic emulsions which determines how long they must be exposed to a given light source to secure equal density when developed. This speed may be given in ASA, DIN, Weston, Scheiner, or AEI scales. END EFFECT [6] EQUAL-ENERGY WHITE [7] An achromatic light corresponding to equal radiance per unit of wavelength at all wavelengths. EQUIVALENT FOCAL LENGTH Same as FOCAL LENGTH and measured to the plane of best average DEFINITION throughout the angular field of the optical system. When a series of color samples varying only in saturation is See also: FOCAL LENGTH presented on a neutral background, the end sample may be perceived EQUIVALENT NEUTRAL DENSITY (END) more saturated than it really is. END is defined as the OPTICAL ENERGY, RADIANT DENSITY that a dye would have if the necessary amounts of the See RADIANT ENERGY other fundamental dyes of a process were added to make it a ENLARGING [4] neutral gray. The process of making a print or negative larger than the original by projection printing. Note: Enlarging colored materials causes colors to become desaturated. EQUIVALENT NEUTRAL PRINTING DENSITY The same as EQUIVALENT NEUTRAL DENSITY (END) except that a printing material is used for visual judgment instead of direct vision. The image of the limiting APERTURE STOP formed in the object space by all optical elements preceding the limiting aperture stop. A type of CHROMATOPSIA or color vision (usually following over- exposure to intense light or prolonged staring at green light) Approved For Release 20C"f lo f"78B04560A007300010028-8 Approved For Release 2003/ :I6 Kl8B0456OA007300010O$ $C/R-01 /72 ERYTHROPSIA (Continued) in which all objects appear tinged with red. Note: Snow-blindness EVEN COLOR Uniformly, the same color over the surface. EXCITATION PURITY The ratio of the distances on a two-dimensional CHROMATICITY DIAGRAM from the adopted light source to the sample color and from the light source to the color lying on the SPECTRUM LOCUS or PURPLE BOUNDARY. Usually indicated by the word "PURITY" alone and is similar to SATURATION. Note: In Figure 2 in the Appendix MN is the Excitation Purity of MP the color N. EXHAUSTION [4] In photography, the state reached by any processing solution when the active ingredient is used up. The image of the limiting APERTURE STOP in an optical system by all the lenses following this stop. Exposure is generally understood to mean the length of time during which light is allowed to act on a sensitive surface. Technically, it is the product of the illumination of a unit area of sensitive surface and the duration of time through which the illumination acts. Note: For colored material exposure is very critical. Even slight over- and under-exposure can affect color balance and fidelity. The time interval between the taking of successive photographs. The range of exposures that can be used for acquiring usable imagery. Determined by the slope of the CHARACTERISTIC CURVE and the D-MAX and D-MIN of the film. Note: In color films the Exposure Latitude is usually very small. EXPOSURE TABLE [4] A table or set of tables to be used as a guide in determining correct photographic exposure. EXTINCTION COEFFICIENT [5] The natural logarithm to the base e of the reciprocal of the trans- missivity. The organ of vision which essentially focuses incoming Approved For Release 2003/ZN F W1304560A007300010028-8 Approved For Release 20edQ( 16ERhftX~P78B04560A00730001 f?-01/72 EYE (Continued) light onto the RETINA where RODS and CONES are stimulated to begin the process of transmitting visual information to the brain. Note: See Figure 1 in the Appendix for the structure of the eye; the parts of the eye are also discussed in the glossary. Approved For Release 20C fWEN4 p78BO456OA007300010028-8 Approved For Release 2003, jj; AL8B04560A007300010028-Z/R-o1/72 f-NUMBER [8] Numerical expression of the rela- tive aperture of a lens at its different stops (also the speed of a lens). The f-number is equal to the FOCAL LENGTH divided by the effective diameter of the lens opening and is written in various forms, e.g., f8, f/8, 1:8, etc. A term applied to colors which have lost their brilliance or vividness (saturation). A temperature scale in which the freezing point of water is 32 degrees and the boiling point is 212 degrees. A film whose colors after processing are intentionally false compared to the colors of the scene. FARBTON (T or F) In the DIN COLOR SYSTEM it is analogous to the concept of HUE. There are 24 Farbtons. FARNSWORTH DICHOTOMOUS TEST FOR COLOR BLINDNESS A test designed to separate color normals from people with slight red-green deficiencies from those who are severely defective. The test is to arrange 15 Munsell papers (varying in HUE but not SATURATION or BRIGHTNESS) in a certain order. People who are color normals will arrange according to HUE, whereas DICHROMATS will arrange according to the saturation differences they perceive. The test allows for a number of people with light to moderate color deficiencies to be passed. A color discrimination test which can classify those with normal color vision into superior, normal, and low color discrimination ability. It can also identify TRITANOPIA, PROTANOPIA, and DEUTERANOPIA but it should be used only to corroborate evidence of color deficiency. The test is to arrange in a certain order 4 sets of 25 MUNSELL papers within a given time limit. FAST [5] Will not fade or change in color on exposure to some named or implied agency such as light. FATIGUE, RETINAL [5] Depletion of the capacity of the retina to respond to light and color. Note: Occurs with prolonged visual work. Approved For Release 200"N1tQ2F XDPZ8BO456OA007300010028-8 Approved For Release 2TO'N 1 E FftAeP78BO456OA0073000T -2-01/72 When an ACHROMATIC light is flickered at low frequencies (about 51/sec) CHROMATIC color sensations may be perceived. These are known as Fechner's Colors. FIDELITY, COLOR See COLOR FIDELITY FIDUCIAL MARKS [4] Index marks (usually four) which are rigidly connected with the camera lens through the camera body and which form images on the negative and usually define the principal point of the photograph. Also, marks (usually four) in any instrument which define the axes whose intersection fixes the principal point of a photograph and fulfill the requirements of interior orientation. FILM BASE [4] A thin, flexible transparent sheet of plastic material which is coated with a light-sensitive emulsion. FILM-COLOR [5] Color seen as soft, non- substantial, indefinitely localized, and texture-free as perceived on a color transparency. FILM SPEED [4] That property of film which determines how much exposure must be allowed for a given light source in order to secure a negative of correct density and contrast. Any transparent material (GLASS, GELATIN, or LIQUID) which by absorption selectively modifies the light transmitted through it. Note: Filters may either absorb wavelengths equally and thus appear (and called) Neutral Gray; or they may selectively absorb certain wavelengths and not others, thus forming a HUE. For example, a red filter absorbs (or filters out) all wavelengths but red (which it transmits). Filters may be used for the following reasons: (1) To correct the imperfect color sensitivity of the film and make it translate the scene into colors that approximate the colors that appear to the eye. Such filters are called CORRECTION FILTERS. (2) To distort (brighten or darken) the reproduction of certain colors for special effects. This intentional distortion is used to enhance contrast. Filters used in this way are called Effect Filters or CONTRAST FILTERS. (3) To change the SPECTRAL DISTRIBUTION of the light which is important in color photography. Such filters are called Color Compensating Filters. Approved For Release 20Q'' F H)EM-WP78B04560A007300010028-8 Approved For Release 2003V ffWj6 Aj8B04560A007300010028-V/R-01/72 FILTER (Continued) Note: Various factors must be considered including light level, (4) To acquire imagery of a color sensitivity of the film, single color only; mainly used for and processing times. scientific and other special purposes such as telephotography FILTERS, GELATIN [8] by infrared light. In principle, most of these filters are extreme The most common camera filters are cases of the contrast filters thin pieces of dyed gelatin. They mentioned above. are easiest to make accurately and offer the widest range of (5) To remove or cut-off a colors. portion of the spectrum. Such Filters are called Cut-off Filters. FILTERS, GELATIN GLASS [8] FILTER, ANTI-VIGNETTING See ANTI-VIGNETTING FILTER FILTER, COLORED [5] A filter which can modify the color of a light by selectively absorbing certain wavelengths and transmitting others. FILTER, COLOR IR FILMS For Color IR films a yellow filter is used to filter out blue wave- lengths. A cut-off of 500 to 520 nanometers should be used. When GELATIN FILTERS have to be constantly handled they are usually cemented between glass. Unless the workmanship of the cementing is good and the glasses are absolutely flat and parallel, the presence of the glass may upset the optical properties of the lens. The best filters for high-quality scientific work are prepared as optical flats of guaranteed accuracy. For most normal photography where such precision is not needed, the gelatin is usually cemented between flat and polished plate glass. FILTERS, COLOR SEPARATION Filters used to obtain COLOR SEPARATION NEGATIVES. They are usually wide-band red, blue, or green filters. FILTER FACTOR [4] A number indicating the exposure increase necessary when using a filter as compared to the exposure necessary under the same conditions without the filter. FILTERS, GLASS [8] The better filters are made from colored glass. Such filters consist of glass only. While they are not so easily damaged as gelatin filters, the range of colors in which they can be manufactured is more limited. Used to reduce the effects of ATMOSPHERIC SCATTERING, they Approved For Release 2003100 W Fat' "04560A007300010028-8 Approved For Release 20E pibEflli P78BO456OA00730001pD28*-01/72 FILTERS, HAZE (Continued) reduce or cut off blue wavelengths. Often called MINUS- BLUE filters. Usually, a filter that does not transmit below 400 nm is used for medium haze and a filter that does not transmit below 420 nm is used for haze at about 12,000 feet. The filters used at extreme altitudes cut off at 450 to 500 nm. However, above 450 run one can expect strong degree of absorption, while the choice of substance gives the necessary absorption characteristics. The main advantage of liquid filters is the exact reproducibility of characteristics. These depend on variables which are easily controlled with great precision: namely cell thickness and the composition and strength of the solutions used. shifts in color balance toward the FILTER, NEUTRAL DENSITY [4] yellow. A deep red filter which absorbs almost all visible light but passes the infrared rays. It should only be used with infrared film. See also: BLACK AND WHITE INFRA- RED FILM A filter which transmits very narrow spectral regions as a result of interfering with the transmission of other wavelengths. FILTERS, LIQUID [8] For specific work special filters may be required which are not obtainable or practical with normal ready-made gelatin or glass filters. It is often more convenient to use solutions of certain colored chemicals in suitable glass cells. The thickness of the cell (i.e., the thickness of solution placed in the path of the light) determines the A filter which absorbs and transmits wavelengths of light equally and is gray in color. Note: These filters can be combined (stacked) to provide a wide range of densities. FILTER OVERLAP [5] The spectral region in which two or more given filters transmit light. FILTER RATIO [4] The ratio between the exposure required to produce the same density on a film when different filters are used. FILTERS, ULTRA-VIOLET (UV) [4] A filter which absorbs the ultra- violet rays but allows all visible light to pass; hence, no increase in exposure time is required when using this filter. Approved For Release 20GFJJDAMdP78B04560A007300010028-8 Approved For Release 2003tOMI FRg[8BO456OA00730001009?it/R-01/72 FIX [4] To render a developed photographic image permanent by removing the unaffected light-sensitive material. A solution which dissolves soluble silver salts from the emulsion leaving a dye image. FIXING [11] The removal of any sensitive substance not acted upon by light or by the developer, thus rendering the emulsion or print unalterable by further action of light. FLARE [4] Non-image light which reaches the photographic emulsion during camera exposures. Its source may be any stray light falling directly on or reflected to the lens or internal lens reflections of image light. Its general effect is to lower the contrast of the image obtained. FLAT [5] A picture or scene which contains little contrast, i.e., the same lightness or darkness or grayness. FLICKER PHOTOMETRY [5] A method of PHOTOMETRY in which two different color stimuli are alternately presented to the eye at a suitable rate; the stimuli are considered equal in luminance when the flicker is minimum. FLIGHT OF COLORS [5] The succession of color perceptions which follows an intense momentary light stimulus viewed against a dark ground. FLUORESCENCE [5] (1) The process by which a material absorbs RADIANT ENERGY and re-emits it in the form of radiant energy of a different wavelength band, all or most of whose wavelengths exceed that of the absorbed energy. (2) The re-emitted radiant energy. Note: Fluorescence, as distinguished from PHOSPHORESCENCE, does not persist for an appreciable time after the end of the excitation process. A fluorescent lamp is an electric discharge lamp in which the RADIANT ENERGY from the electric discharge is transferred by suitable materials (phosphors) into wavelengths giving higher LUMINOSITY. Note: See Figure below for spectral distribution of a "DAYLIGHT" Fluorescent Lamp. Approved For Release 20031W6N4I.UA`Xl 48BO456OA007300010028-8 Approved For Release 2(%I lIBEpfffAeP78BO456OA0073000 -8-01/72 FLUORESCENT LAMP (Continued) Wavelengths, nm FLUX Rate of transfer of energy See Also: RADIANT FLUX; LUMINOUS FLUX FOCAL LENGTH [4] The distance measured along the optical axis from the optical center (rear NODAL POINT) of the lens to the plane of critical focus on a very distant object. Note: See Figure below; F is the focal length. HF-H FOCAL PLANE [8] Imaginary plane on which a lens forms a sharp image when correctly focused. For sharp pictures the emulsion surface of the plate or film in a camera must be accurately positioned in the focal plane of the lens. FOCAL POINT (PRINCIPAL FOCUS) [8] Point of intersection of all rays of light transmitted by a lens from a given object point. When the object is at infinity and the incident rays are parallel to the lens axis, the image is the Principal Focal Point and lies on the axis of the lens. Note: See Figure below. FOCUS [4] Principal Focal Point (1) The point at which the rays from a point source of light reunite'and cross after passing through a camera lens. In practice, the plane in which a sharp image of any scene is formed. (2) To make adjustments to have the FOCAL PLANE and the emulsion layer coincide. Approved For Release 20 f1U)XMDP78BO456OA007300010028-8 Approved For Release 2003/A /.1.41 P[8BO456OA00730001009?*/R-01/72 FOG [4] (1) A fault in a negative seen as a veil over the whole negative either as darkened patches or as an obscuring of shadows (light areas in the negatives). It may be due to light accidentally reaching the negative .(light fog), to an error in compounding or using solutions, or to gradual degeneration of the film or developer with age. (2) A mist composed of water- vapor particles which may also contain dust and smoke. FOOT-CANDLE [8] A unit of ILLUMINANCE representing the light intensity over a surface one foot away from a standard CANDLE. It is equal to 1 LUMEN per square foot (1 lumen/ft2) or 1.0764 x 10-3 LUX. Note: See Table 1 in the Appendix. See Also: LUMEN, LUX. FOOT-LAMBERT A unit of LUMINANCE equal to 1 candela/ft2. It is also equal Tr to 1.0764 millilamberts, or 3.4263 candela/m2. Note: See Table 1 in the Appendix. See Also: LAMBERT; METER-LAMBERT A quick color vision test for normalcy of yellow-blue and red-green vision. FOVEA (FOVEA CENTRALIS) [5] A small ellipse-shaped depression in the central region of the RETINA which measures somewhat less than a degree of visual angle at its maximum diameter and is characterized by the sharpest CONE vision. Note: The Fovea is the center for visual fixation and attention and is practically 100% CONES. See Figure 2 in the Appendix. FOVEAL CONES Cones lying in the FOVEA. FREEMAN ILLUMINANT-STABLE COLOR VISION TEST A PSEUDO-ISOCHROMATIC test which separates color normals from red- green deficiencies. This test gives comparable results under several types of illuminants (COLOR TEMPERATURE of 2,000 K to 4,000 K). However, some dot patterns may be unfamiliar to many people who take the test. FRINGE (RAINBOW EFFECT) A defect of a color picture where edges are multicolored resulting from lack of registration of the component images. A fringe may be caused by parallax, error in Approved For Release 2003/W FkBhbkbl*hBO456OA007300010028-8 Approved For Release 20Q, (R~itt~ tIRQP78BO456OA007300011"?P/4_01/72 FRINGE (RAINBOW EFFECT) (Continued) printing registration, or by movements of the object between the exposure or COLOR-SEPARATION NEGATIVES or ADDITIVE COLOR SEPARATIONS. FULL APERTURE [4] The maximum opening of a lens or lens diaphragm. In the OSTWALD COLOR SYSTEM it describes the maximum saturation of a HUE. Color Content is the dimension analogous to SATURATION. The set of three spectral sensitivity or mixture curves (one each for red, blue, and green sensitivities), usually plotted with relative luminosity as a function of wavelength, which represent the actual sensitivities of the fundamental retinal response processes, according to tri-receptor theories of color vision. The maxima of these response curves are believed to be 450, 540, and 590 nanometers, respectively. Approved For Release 20MiFM) BW78BO456OA007300010028-8 Approved For Release 2003tfyQg[78B04560A0073000100?Vf1~/R-01/72 GAMMA [4] A numerical designation for the CONTRAST of a photographic material as represented by the slope of the STRAIGHT-LINE portion GELATIN [4] A transparent colloid which swells to a jelly-like mass in cold water but dissolves in hot water. Used as a medium for the silver salts in coating plates, films, and sensitized papers. GELATIN FILTERS [5] A filter in which gelatin is used as the vehicle for the absorbing material. lightness range in the negative is one-half of the lightness range in GENERAL COLOR [5] the scene. of the CHARACTERISTIC CURVE. Gamma is numerically equal to the tangent of the angle which the straight-line portion makes with the base line. A gamma of 1 in a negative signifies that the lightness range in the negative is the same as the range of light values in the scene photographed; a gamma of .5 signifies that the A term applied to the tonality of See Also: CHARACTERISTIC CURVE a whole image. GANGLION CELLS [4] Note: The general color of a jungle image is green. The second layer of nerves leading away from the RODS and CONES which GENICULATE BODIES, LATERAL are activated by the BIPOLAR CELLS. Their axions pass across the inner retina and out of the eyeball to form the OPTIC NERVE. GAP [4] A pair of tissue bodies lying within the thalamus (portion of the brain) where the OPTIC NERVE connects with the OPTIC RADIATIONS. Any space where aerial photographs GEOMETRIC METAMERISM fail to meet minimum coverage requirements. This may be a space GLARE [5] not obtained. The disturbance of the sensitivity of the eye experienced when portions of the field of view have a brightness not covered by any photograph or a space where the minimum specified overlap or sidelap was Approved For Release 2003c QNi1 &ll lb F8B04560A007300010028-8 Approved For Release 20mofbaptfff 781304560A00730001(R-01/72 GLARE [5] (Continued) or intensity greatly in excess of that of the average. Note: Glare, as such, does not occur on images or prints, although one can identify glare from objects in the scene. Translucent dye particles in colored transparencies. GLOSS [5] The light reflected from_the fullest black on a glazed print is of the order of 1-2 percent of the incident light, while on a matt print it is around 5-10 percent. Assuming a maximum reflectivity of 80-90 percent from the pure white paper, the brightness range of a glossy print can be as high as 50 : 1 and of a matt print about 15 : 1 or 10 : 1. The increased brightness range is important in copying or photo- mechanical reproduction and it explains why prints on glossy paper always reproduce best. The glossy surface has its dis- Property of a surface which reflects advantages: it shows up detail; a substantial proportion of the and it tends to emphasize grain- incident light in a mirror direction iness, scratches, and other which is responsible for its shiny blemishes. Underexposed shadow or lustrous appearance. areas show up as featureless black patches on glossy paper. GLOSSY PAPER [8] GODLOVE SMALL-COLOR-DIFFERENCE Photographic printing paper with FORMULA a smooth shiny surface that can be further emphasized by glazing. A formula used to compute color Note: A glossy surface is devoid of surface texture and is thus invisible-- like the surface of a polished mirror. It therefore shows up all the detail in the photograph. Since the smooth sur- face does not scatter light, a glossy print is better than a rough surface print because it shows brighter colors, is able to cover a greater brightness range, and can reproduce shadow detail better. differences from differences in the MUNSELL HUE, VALUE, and CHROMA of the two colors being compared. GONIOPHOTOMETER [5] A device that measures directional reflectance and directional transmittance of a surface with collection of light confined to a narrow range of angles, the central ray of which is variable over a wide range of angles relative to the surface of the test specimen. Approved For Release 20c )N'FIDEWTlk b78BO456OA007300010028-8 Approved For Release 2003tV"ll5Al8BO456OA00730001002838;/R-01/72 GOST SPEED [8] Film speed rating in use in the (1) One of the discrete silver Soviet Union and some eastern particles resulting from the European countries. GOST speeds development of an exposed light- are quoted on an arithmetical sensitive material. scale and are fairly similar to the ASA arithmetical speed numbers. The GOST Speed criterion is based on the exposure point corresponding to a specified minimum density above base plus fog of the film. (2) This term may also be used with color images, although the grain is really a DYE GLOBULE. Note: Grains have definite edges where globules are translucent and, thus, appear different under high magnification. Term referring to the TONE scale GRAININESS (GRAINY) The mealy appearance of the image caused by the clumping together of the silver grains or, in color transparencies, the clumping together of the GLOBULES. between the extreme dark and light GRAM (METRIC SYSTEM) [4] tones, it is said to have a Hard Gradation. The international unit of weight. or CONTRAST range of a developed image. An image which shows a large number of intermediate tones of gray between the extreme dark and light tones is said to have a Soft Gradation; if there are only a few recognizable shades of gray Note: The Gradation of an emulsion is at once obvious from the steepness of its CHARACTERISTIC CURVE(S). An emulsion with a steep curve(s) will possess a harder gradation than one with a shallow curve(s). GRADIENT [4] Applied to the CHARACTERISTIC CURVE, the slope of any chosen part of the curve; distinguished from GAMMA which refers to the slope of the STRAIGHT-LINE portion of the curve only. It is the weight of a cubic centi- meter of pure water at its maximum density. It is equal to 15.432 grains AVOIRDUPOIS. A term referring to the granular structure of the sensitive emulsion as represented by the measured variation in the distribution of an apparently uniform silver or DYE GLOBULE deposit. Note: It is a scientific concept whereas GRAININESS is a subjective visual impression created by the granular structure of a photographed material. Approved For Release 2003/65/1I1FI6l .N EJl8BO456OA007300010028-8 Approved For Release 20e (Q 1btWtIWTP78BO456OA007300011Q19 fa._01/72 GRASSMANN'S LAWS (2) Any hue predominantly similar to GREEN. The laws of ADDITIVE COLOR MIXTURE as stated by Grassmann in 1855 and serving as a basis for the science of COLORIMETRY. Of these laws the (3) The complement of MAGENTA or PURPLE. most important are (a) lights of GREEN-BLINDNESS the same color produce identical effects in mixtures regardless of their spectral composition; (b) two lights of the same color, added to two other lights of the same color, produce mixtures that likewise have the same colors ; (c) two lights of the same color, each subtracted respectively from mixtures of equal color, leave remainders that color-match; and, (d) if one component of a two- component mixture is steadily changed (while the other remains constant), the color of the mixture See DEUTERANOPIA GREEN FILM [4] Newly developed film which, although apparently dry, still contains a considerable amount of moisture. Even in a warm room film does not become completely dry in less than 6 to 12 hours, and it is best not to attempt printing or enlargement of film sooner than this. steadily changes. GROUND [5] GRAY [5] (1) The focused or unfocused surroundings of a figure or An ACHROMATIC COLOR of any light- object perceived as lying beyond' ness intermediate between the and not belonging to the figure extremes of black and white. or object. GRAY SCALE [4] (2) The earth as seen on high- altitude imagery. A series of ACHROMATIC COLORS ranging from white to black with intermediate tones of gray. See Also: STEP WEDGE; WEDGE GREEN [5] (1) The hue attribute of visual sensations typically evoked by stimulation of the approximately normal retina with radiation of wavelength 513 nm. Approved For Release 20MIH} P78BO456OA007300010028-8 Approved For Release 2003/eefWi6AJ8B04560A007300010028-&/R-o1 /72 H. & D. CURVE [4] (1) A Hurter and Driffield graph showing the relationship of exposure and density where the density is plotted against the logarithm of the exposure. (2) See CHARACTERISTIC CURVE HALATION[4] development. It is used after DEVELOPMENT and before FIXING. HARDNESS [4] In negatives and prints too much Contrast; too great a difference between lights and shadows; too steep a GRADATION. HARDY-RAND-RITTLER PSEUDO- ISOCHROMATIC PLATE TEST A fault of film in which the high- lights are blurred and encroach upon the surrounding shadows. It is caused by the scattering of light by the silver halide crystals and by the reflection of the film on the back of the camera platen. Note: On color films, bright colors of highlight areas may appear smeared. HARDENING BATH (HARDENER) A solution used to harden the gelatin on the emulsion. HARDENING FIXER [8] Fixing bath, particularly one for fixing negatives, that contains a hardener so that the emulsion is hardened and rendered less liable to injury in subsequent washing, drying, and handling. HARDENING STOP BATH [11] A HARDENING BATH that also contains an acid to arrest the progress of A test to distinguish types and degrees of red-green and yellow- blue color deficiencies. It uses simple designs in colored dots on colored dot backgrounds and has been used with children, foreigners, and illiterates. The suspension of moisture, dust, and other matter in the atmosphere which scatters ultraviolet, violet, and blue wavelengths of light. Longer wavelengths of light, such as red, are less affected. Note: Haze causes high-altitude and oblique color images to have a bluish overcast, reducing color fidelity and balance. See Also: FILTER, HAZE; RAYLIEGH SCATTERING; MIE SCATTERING HEIGHTEN [5] To heighten a color is to increase its intensity. Approved For Release 20031 W.ID JAA8BO456OA007300010028-8 Approved For Release 2 / E ffin--PP78BO456OA0073000 QW 01/72 HERING GRAYS [5] A set of 50 neutral gray papers graded from extreme white to extreme black in steps which approximate subjective equality. The set represents the ACHROMATIC series of colors. HERING THEORY OF VISION [5] The theory proposed by E. Hering and modified by later writers, according to which colors are due to three pairs of antagonistic processes in the optic system, one member of each pair being destructive, the other construc- tive, the pairs yielding respectively, white and black, yellow and blue, and red and green. Thus we see yellowish and bluish colors but not both at the same time (yellow cancels blue and vice-versa). Similarly we see reddish and greenish colors but never both at the same time (red cancels green and vice versa), etc. Note: This theory predicts a form of yellow-blue blindness (TETARANOPIA) of which no uncom- plicated case has ever been reported. Yet it fails to predict Measurement of the intensity of colored light sources using a PHOTOMETER. HETEROCHROMIC [5] Same as DICHROMATISM (definition 2) but can apply to samples having more than two shades as a function of change in concentration. HIGHLIGHTS [4] The densest parts of a negative and the lightest parts of a print or positive transparency. A test to separate color normals from green-red defectives which involves the matching of skeins of different-colored yarn with three standard skeins (red, green- yellow, and purple). Note: The test has not been standardized in terms of the skein colors and detects only about half the color defectives examined [6]. two of the chief types of HOMOCHROMATIC DICHROMATIC VISION (PROTANOPIA and TRITANOPIA). See Table 2 in the Appendix. A color of single HUE and SATURATION but can vary in BRIGHTNESS. See Also: HURVICH-JAMESON QUANTITATIVE OPPONENT COLORS THEORY HOMOCHROMATIC AFTER-IMAGE [11] HETEROCHROMATIC See AFTER-IMAGE, POSITIVE Colors which vary in both HUE and SATURATION. Approved For Release 20? 1HID 78B04560A007300010028-8 Approved For Release 2003/Qfltfft 41j fg78BO456OA007300010Q TO/R-01/72 HORNER'S LAW [5] A principle of the inheritance of color-blindness according to which the common types are transmitted from males to males through unaffected females (via a sex- linked recessive gene). HUE [4] (1) That attribute of a CHROMATIC COLOR by virtue of which it differs from gray of the same lightness and which allows it to be classed as red, yellow, green, blue, or intermediate mixes of these SPECTRAL COLORS. (2) A dimension in the MUNSELL COLOR SYSTEM of uniform perceptual steps in hue. (3) Analogous to DOMINANT WAVE- LENGTH. HUE THRESHOLD, DIFFERENTIAL The just-perceived wavelength difference in Hues at constant purity and luminance (saturation and brightness) expressed in nanometers. Note: Generally, .1 to .2 nm are required over most of the spectrum but up to .6 nm at the extremes. See the Figure below: 500 550 ?00 650 /nm Differential color sensitivity throughout the spectrum, according to Wright and Pitt. Wright's colorimeter, free from diffused light, 2? field, average retinal illumination 70 trolands except in the extreme blue, method of limits. From LeGrand, Yves, Light, Colour and Vision, Fig. 73, p. 275. (Translated by R.W.G. Hunt, J.W.T. Walsh, and F.R.W. Hunt, New York; John Wiley & Sons, Inc., 1957.) HURVICH-JAMESON QUANTITATIVE OPPONENT COLORS THEORY A quantitative expression of the HERING THEORY OF VISION which has been the most successful in explaining quantitatively recorded facts of color vision. Note: The criticisms of it are the same as the HERING THEORY OF VISION (which see). See Table 2 in the Appendix. HYPERFOCAL DISTANCE [4] If an object at a great distance (infinity) can be sharply focused, it is found that, without' altering the position of the lens,. Approved For Release 2003/cFF I-$ ,B04560A007300010028-8 Approved For Release 2?Q31Qf54 :O,RDP78B04560A00730004P4aPR801/72 HYPERFOCAL DISTANCE [4] a comparatively near object is still "in focus"; that is, it is rendered without perceptible unsharpness. The distance to this near point is the hyperfocal distance. HYPERSENSITIZING [4] A term applied to various methods of increasing the sensitivity and SPEED of an unexposed emulsion; for example, fuming or bathing with ammonia, fuming with mercury, etc. Approved For Release 2CONF41. AVP78BO456OA007300010028-8 Approved For Release 2003/tb' F lflftMW70B0456OA007300010044%'?C/R-01/72 ICI [5] Abbreviation for the International Commission on Illumination. Note: The French title of the ICI, Commission Internationale de 1'Eclairage, and its abbreviation CIE is commonly used but rarely the German title (Internationale Beleuchtungs-Kommission) or its abbreviation IBK. The light being sensed or perceived by the visual system when there is no external source of light. Caused by the continuous physiological activity of the visual system. ILLUMINANCE [5] LUMINOUS FLUX incident per unit area of surface. Note: This quantity has commonly been called illumination in the past. Usual units are the LUX or LUMENS per square meter. See Figure 4 in the Appendix. In the CIE system, light defined by its SPECTRAL POWER DISTRIBUTION, in contrast to a source, which is a physically realizable object emitting RADIANT POWER. ILLUMINANT COLOR [5] Color seen as glowing, luminous, or belonging.to light source, e.g., a colored light bulb. ILLUMINANT-COLOR PERCEPTION [5] Color perceived as belonging to a source of light. ILLUMINANT, STANDARD See STANDARD ILLUMINANT ILLUMINATION See ILLUMINANCE ILLUMINATION COLOR [5] Color seen as belonging to illumination distributed in space, e.g., color of sunlight in a room, red light flooding a stage, etc. ILLUMINATION-COLOR PERCEPTION [5] The principle that the ILLUMINANCE of a surface varies directly as the INTENSITY of the light source, inversely as the square of its The awareness of the distribution of colored light in space. distance, and directly as the IMAGE cosine of the angle made by the light-rays with the perpendicular to the surface. The counterpart of a scene produced on film by the reflection See Also: INVERSE SQUARE LAW Approved For Release 2003A9/1M 1 Q I EIA18BO456OA007300010028-8 Approved For Release 2QQ ,(p,5ibtOARDP78B04560A0073000g998PR801/72 IMAGE (Continued) or refraction of light when focused by alens or mirror. IMAGE, LATENT The emission of light from a heated solid or liquid. Its SPECTRAL DISTRIBUTION or color is dependent on its temperature, e.g., a tungsten filament lamp. An invisible image on exposed but undeveloped film or print that can INCANDESCENT TUNGSTEN LIGHT be revealed by DEVELOPMENT. IMAGE-MOTION COMPENSATOR (I.M.C.) [4l A device installed with certain aerial cameras to compensate for the forward motion of an aircraft while photographing ground objects. True image-motion compensation must be introduced after the camera is oriented to the flight track of the aircraft and the camera is fully stabilized. IMAGE, RETINAL The optical image of an external scene focused upon the RETINA by the refracting surface (lens) of the eye. IMBIBITION [5] (1) A process for producing a dye-image by mechanical printing. A dyed relief or differentially tanned matrix of some substance such as gelatin is brought into intimate contact with a moist absorbing layer, the dye diffusing from the matrix to the absorbing layer. (2) To absorb or assimilate moisture, gas, light, etc. Light emitted by a tungsten filament. Wavelength/relative power distribution varies with temperature of the filament. Note: In the Figure below are spectral power distribution curves for (a) 25-Watt, (b) 50- Watt, (c) 500-Watt, and (d) 1000- Watt lamps. Of I 0L L 400 500 600 700 Wavelength (nm) INCIDENCE, ANGLE OF [5] The angle between the path of an oncoming ray of light and the normal to the surface on which it impinges. Note: Angle A is angle of incidence. Approved For Release 2 I ENlNAwP78BO456OA007300010028-8 Approved For Release 20031 f3}f OMw B04560A0073000100*?C/R-01 /72 INCIDENCE, ANGLE OF [5] (Continued) INDUCED COLOR See Also: SNELL'S LAW INCIDENT FLUX The rate at which radiant energy strikes a surface. INCOMPLETE RADIATOR A RADIATOR that emits less power than a BLACKBODY at the same temperature. INDEX OF REFRACTION See REFRACTIVE INDEX INDIRECT COLORIMETRY The measurement of a color using indirect means. Note: The color of a nonself- luminous object can be computed A color or change in color which appears in a given portion of the subjective visual field not caused by direct stimulation of the cor- responding portion of the retina, but caused by the stimulation of the surrounding retina. Note: Colors as perceived may be affected by adjacent colors. For example, yellow will appear darker in a black surround than in a gray surround. The darker yellow is the Induced Color. See Also: SIMULTANEOUS COLOR CONTRAST The color which affects the per- ceived appearance of an adjacent color. Note: Distinguished from INDUCED COLOR, the color that causes the effect. from its SPECTRAL REFLECTANCE (or INFINITY [4] transmittance), the SPECTRAL POWER DISTRIBUTION of the illuminant, and the CIE COLOR MATCHING FUNCTIONS for the spectrum. These calculations consist of summing the products of these three groups of data, wavelength by wavelength one complete calculation for each of the three PRIMARIES. In photography, an indefinitely great distance; a distance so great that rays from a point source of light at that distance are parallel for all practical purposes. For most lenses and most types of work, any distance 1,000 times the focal length may be safely regarded as infinity. Approved For Release 2003/MFIDEN MB0456OA007300010028-8 Approved For Release 2Q.Q3L0f4DP78B04560A00730004PQ@PR$01/72 Term sometimes used to describe emulsions sensitive to infrared radiations, as used for infrared photography. IR Abbreviation for "INFRARED". INFRARED (IR) Pertaining to or designating the portion of the electromagnetic spectrum with wavelengths just beyond the red end of the visible spectrum, such as radiation emitted by a hot body. Their wavelengths are longer than those of visible light and shorter than those of radio waves. Light rays whose wavelength is greater than 700 nanometers. Invisible to the eye, infrared rays are detected by their thermal and photographic effects. Note: There are films which are sensitive to the IR wavelengths which image in black and white and FALSE-COLOR. These films generally image live vegetation as a particular shade of color such that living vegetation can be detected easier and be distin- guished from most other targets and backgrounds. See Also: COLOR INFRARED FILM; BLACK AND WHITE INFRARED FILM The use of an instrument to determine the CIE TRISTIMULUS VALUES X, Y, AND Z for a given transparency or opaque sample. The two most frequently used instruments are the RECORDING SPECTROPHOTOMETER and the TRISTIMULUS COLORIMETER. See METAMERISM, INSTRUMENTAL; METAMERISM, GEOMETRIC INTEGRAL DENSITOMETRY (INTEGRAL DENSITIES) The measurement of integral densities. They are the result of the combined or net effect of the superimposed dyes in a color film with no attempt to separate the effects of a single dye from the total density. Four types of integral densities are commonly used: INTEGRAL SPECTRAL DENSITIES, PRINTING DENSITIES, COLORIMETRIC DENSITIES, and ARBITRARY THREE- FILTER DENSITIES. See Also: (See above four densities) INTEGRAL DENSITIES measured by a DENSITOMETER whose response approximates the photographic response of the printing or duplicating material. These may also be calculated mathematically by using equations which take into account the characteristics of the duplicating material. The density measured, wavelength- by-wavelength, on all the fundamental dyes in a material. Approved For Release 2CO?'p1 I ENINAOP78BO456OA007300010028-8 Approved For Release 2003T5(WI6NW B04560A00730001 00%PC/R-01/72 INTEGRAL SPECTRAL DENSITIES (Cont'd) INTER-IMAGE EFFECTS A SPECTROPHOTOMETER or similar device capable of narrow-band, wavelength separations is required. An optical device used in a SPECTROPHOTOMETER to collect light reflected from an opaque sample. INTENSITY, OF LIGHT The amount of RADIANT ENERGY per unit area. The higher the amount, the greater the intensity. The interaction, during processing, of the chemical reactions that are occuring in each of the emulsion layers of a multilayer film. For example, the chemical reaction that develops the magenta image may also cause some undesired development of the cyan image in the next emulsion layer. Note: These interactions are gen- erally taken into account and used as beneficial design characteris- tics. See Also: ILLUMINANCE; LUMINANCE; CANDLE POWER. An effect resulting from the meeting of two light rays of identical wavelength but different phase; when the phase difference is 1/2 wavelength, the two light waves cancel and darkness results; interference between two rays of HETEROCHROMATIC light results in colored patterns similar to the SPECTRUM produced by a PRISM. INTERFERENCE COLORS 15] Colors resulting from the destruc- tion of the light of certain wave- lengths and the augmentation of the light of others by INTERFERENCE. INTERFERENCE FILTER Reflection of light from the various glass surfaces of a compound lens. Such reflection cuts down the illu- mination passing through the com- pound lens. INTERNAL TRANSMITTANCE See TRANSMITTANCE, INTERNAL INTERNAL TRANSMISSION FACTOR [5] The ratio of the LUMINOUS FLUX reaching the second surface of a transparent body to the luminous flux leaving the first surface. Note: In the Figure below, the ratio of the flux at A to that at B. A Approved For Release 200fONRIMU bW8BO456OA007300010028-8 Approved For Release 2 eQ [Q, i t WfW P78B04560A007300 ?,$01 /72 An international unit of light intensity (see CANDELA). INTERPUPILLARY DISTANCE (INTEROCULAR DISTANCE) [12] The distance between the pupils of the eye of an individual. The range is from 2.2 to 3.0 inches. INTERVALOMETER [4] A device used on aerial cameras which automatically operates the shutter at predetermined intervals. INVARIABLE HUES [6] INVERSE SQUARE LAW [4] The illuminance of a unit surface and, consequently, the brightness of the surface vary inversely with the square of the distance from a point of light source. See Also: ILLUMINANCE, LAW OF IRIDESCENT [5] Changing color with position. Usually applied to colors produced by INTERFERENCE, REFRACTION, or DIFFRACTION. Note: Such as the rainbow of colors on a soap bubble or on an oil film on water. Certain wavelengths produce hues which do not change as far out on IRIS the retina as saturation is elicited. These wavelengths are A part of the CILIARY BODY which approximately 464 nm, 489 nm, and has a central circular aperture 571 nm. called the PUPIL which is the APERTURE STOP of the eye. Note: See Figure 1 in the Appendix. The Invariant Hues are those which are independent of the BEZOLD- IRIS DIAPHRAGM [4] BRUCKE phenomenon, i.e., those hues which do not change with a change A lens control composed of a series in luminance of the stimulus. of overlapping leaves operated by In general, the HUES correspond to a revolving ring to vary the the following wavelengths: 474 nm aperture of the lens. (blue), 506 nm (green), 571 nm (yellow), and a complementary IRRADIANCE wavelength of 495 nm (red). The RADIANT FLUX incident per unit See Also: BEZOLD-BRUCKE PHENOMENON area of a surface. INVARIANT MATCH IRRADIANCE, SPECTRAL A COLOR MATCH which is agreed upon The RADIANT FLUX per unit wave= by all people under all illuminants. length incident on a unit area of surface. Approved For Release 2 'J?ENi 4AlP78B04560A007300010028-8 Approved For Release 20031 eJ 16 R18B0456OA0073000100'- /R-O1 /72 (1) The spreading of light in an emulsion caused by reflection from the surfaces of the silver halide crystals. The slight blurring caused by irradiation should not be confused with the more notice- able and extensive blurring known as HALATION which is caused by reflection from the back surface of the plate or film on which the emulsion is supported. (2) The perceived spreading of brighter colors onto their darker surround which may slightly enlarge the perceived size of the brighter color. ISCC-NBS(INTER-SOCIETY COLOR COUNCIL- NATIONAL BUREAU OF STANDARDS) COLOR DESIGNATION Designation of a color by simple English words according to a method devised by the Inter-Society Color Council and worked out in detail at the National Bureau of Standards. The 267 color names used include a number of hue names plus the adjectives light, medium, dark, pale, grayish, blackish, moderate, brilliant, strong, deep, and vivid. These color names are related to specific regions in the MUNSELL COLOR SYSTEM. (3) The process by which radiant A test to distinguish green-red energy is made to be incident upol color deficiency from normal color a surface. vision. It is a PSEUDO- ISCC (INTER-SOCIETY COLOR COUNCIL) COLOR APTITUDE TEST ISOCHROMATIC PLATE color test. ISOCHROMATIC [4] A test used to measure the abilit~ Of equal color. to discriminate saturation dif- ferences and scored according to ISOMERIC COLORS the accuracy of saturation matche . Colors whose SPECTRAL DISTRIBUTIONS are the same and have identical TRISTIMULUS VALUES X, Y, and Z. Not a recommended term. drawn from an identical set of 48 ISOMERIC PAIR The examinee is instructed to match on a panel of 48 colored chips (involving 4 HUES, each wits a set of chips varying in SATURATION) a colored chip he has colors. People can be sorted into five groups according to satura- tion discrimination: low, satisf c- tory, good, excellent, and exceptional. Two colors of identical SPECTRAL DISTRIBUTIONS and TRISTIMULUS VALUES X, Y, and Z. Not a recommended term. Approved For Release 200L1 RID N-T 8BO456OA007300010028-8 Approved For Release 2?(3$ /I'5E. ffilffP78BO456OA0073000tQM38.01/72 ISOPAQUE CURVE [51 A line connecting a series of points of equal opacity. Such curves when applied to spectrograms may be used to demonstrate the color sensitivity of photographic materials. Approved For Release 20COUT1IO P78BO456OA007300010028-8 Approved For Release 20031 ei i O A18BO456OA0073000100 j> /R-01 /72 JUST-NOTICEABLE DIFFERENCE (JUST-PERCEPTIBLE DIFFERENCE) [5] The least difference in value between two compared stimuli which (in a given individual) gives rise to two different sensations 50% of the times presented. Abbreviated j.n.d. Note: For example the j.n.d. of two spectral green colors is about 1 to 2 nanometers. Approved For Release 2003 1 N4II Ek b k8BO456OA007300010028-8 Approved For Release 2e( ff4f DP78B04560A0073000NIOD2s 801/72 KELVIN (K) A temperature scale starting at absolute zero (approximately -273 C) and having a degree of the same magnitude as those of the CELSIUS scale. Thus 0 C = 273 K; 100 C = 373 K. According to con- vention, the degree sign and the word degree are now omitted in all references to Kelvin temperatures. See Also: ABSOLUTE TEMPERATURE KILOWATT 1,000 watts. KIRCHOFF'S LAW [5] Ratio of RADIANT EMITTANCE to RADIANT ABSORPTANCE is the same for all surfaces at the same temperature. KODACHROME [8] Pioneer SUBTRACTIVE reversal process of color photography worked out by L. D. Mannes and L. Godowsky and introduced by Kodak in 1935. It makes use of an integral TRIPACK in which the emulsions contain no color formers but are subject to individual dye development. KODACOLOR [8] (2) The name is now applied to a negative-to-positive process for making positive color prints. KODAK [8] Trade name of USA Eastman Kodak Co., coined by George Eastman, founder of the organization, in 1888 and first registered in Great Britain on May 3, 1888, then in the United States on September 4, 1888, and subsequently in many other countries. It was first used in connection with Eastman's original box-type camera. Eastman was determined to adopt a trademark that could not be mis- spelled or mispronounced in any language, or infringed or copied by anyone. He wanted a strong word that could be registered and that people would not forget. A two-flux turbid medium theory for describing the way light interacts with any medium which both scatters and absorbs it. Describes the reflectance and transmittance of translucent materials in terms of a scattering coefficient and an absorption coefficient K. In the limiting case of opaque materials, K (1-R)2 (1) Originally an additive method S __ 2R ith h h d i l of the otograp s w ng co or p pro uc aid of a lenticular screen where R is the reflectance of the embossed on the front of the film. It was first made available commercially in 1928 on 16 mm. cine film. sample. For colored samples where R, K, and S depend upon the wavelength, the Kubelka-Munk Approved For Release 26NEA'QEN1iAP78B04560A007300010028-8 Approved For Release 200 g5(ap1f,GJffW8B04560A007300010( t /R-01/72 KUBELKA-MUNK ANALYSIS (Continued) Analysis can be used to formulate the mixture of colorants (dyes or pigments) to produce a specified color. Works well for paints, plastics, paper textiles, and many other systems. Approved For Release 20011?1hI DEiN- 78B04560A007300010028-8 Approved For Release 20M~ r,l/ 1 P78B04560A00730001 Pi -01/72 LADD-FRANKLIN THEORY OF COLOR VISION [5] LATERAL GENICULATE BODY A theory which assumes that in the retinal nerve endings the respec- See GENICULATE BODIES, LATERAL tive light stimuli liberate red-, green-, and blue-stimulating LATERAL-OBLIQUE PHOTOGRAPH [12] substances from a complex photo- sensitive molecule and that red An oblique aerial photograph taken and green, when present, unite to with the camera axis as nearly form a yellow-stimulating sub- normal as possible to the flight stance. According to this theory, line. blue and green, or blue and red cannot unite so, and do not LATITUDE individually disappear in the respective blue-green and blue- See EXPOSURE LATITUDE red (or purple) mixtures. All colors are produced by various mix- LEADER [12] tures of these liberated substances. A strip of material at the Note: See Table 2 in the Appendix. beginning of a roll of film which is used to assist the threading of the film through the camera and processing equipment. The lambert is a unit of surface LUMINANCE equal to 1/'r candela per LENS .square centimeter. Note: See Table 1 in the Appendix. See Also: FOOT-LAMBERT; METER- LAMBERT LATENT IMAGE See IMAGE, LATENT LATERAL-CHROMATIC ABERRATION [4] A lens aberration which affects the sharpness of images off the OPTICAL AXIS because different colors undergo different magnifications. (1) A transparent object (usually made of glass, fluorite, or quartz) having two polished surfaces of which at least one is curved. It is shaped so that the rays of light when passing through it are made to converge or diverge. (2) See CRYSTALLINE LENS LENS ELEMENT [12] One lens of a complex lens system. In a photographic lens, the terms front element and rear element are often used. Approved For Release 200(1 ftf ?f IRTW78B04560A007300010028-8 Approved For Release 2003t6#166 QR78B0456OA0073000100R?*/R-01/72 LEUCO-BASE See Also: ADAPTATION, LIGHT; PHOTOPIC VISION A white or slightly colored sub- stance which upon oxidation LIGHT WAVES (sometimes accompanied by reaction with an acid or base) yields a Light when regarded as an more highly colored dye. undulatory or wave-like phenomenon. LIGHT [1] LIGHTNESS (1) The aspect of RADIANT ENERGY or the portion of the ELECTRO- MAGNETIC SPECTRUM of which a human observer is aware through the visual sensations that arise from the stimulation of the RETINA of the eye. (2) Used in reference to colors having brightness values near white, such as light red, light blue, etc. (3) Diffusely reflecting a relatively large amount of the incident light. (4) The opposite of dark. LIGHT ADAPTATION See ADAPTATION, LIGHT LIGHT-ADAPTED EYE [5] (1) The attribute which permits a surface color (CHROMATIC or ACHROMATIC) to be classified as equivalent to some member of the series of grays ranging from black to white. (2) The attribute of color perception by means of which an object is judged to reflect light rather than another object. LIMEN Same as THRESHOLD See Also: DIFFERENCE LIMEN LINE PAIR In resolution targets, the width of one line and one space in a parallel line target. Normally the line-width and space-width are equal. An eye which has been exposed to light stimuli of relatively high intensity and therefore has become relatively insensitive to lower intensities. Note: For judging or naming color light-adapted eyes are necessary because color perception is absent in the dark-adapted eye. Note: In the Figure below, A and B form a line pair. Approved For Release 200aCON f I t*k8BO456OA007300010028-8 Approved For Release 2003J/, DMQI?78B04560A007300010RM/R-01/72 LIVID COLOR [5] A leaden tint (blue, violet, or green) approaching black. LOCI OF CONSTANT HUE [18] Curves on the CHROMATICITY DIAGRAM representing colors that have same hue under prescribed conditions. LOCI OF CONSTANT SATURATION [18] Curves on the CHROMATICITY DIAGRAM representing colors that have same saturation under prescribed condi- tions. LOGARITHM (LOG) [4] The exponent that indicates the power to which a fixed number must be raised to obtain a given number. and yellow). The glasses within each set vary in optical density and are designated numerically (1R, 2R, 1B, 2B, lY, 2Y, etc.) so that the numbers are additive (1B+2B = 3B, etc.) and any com- bination with equal numerical values of all three colors yields a neutral (achromatic) color. By combining these glasses properly most colors can be matched. For example, a red color might be matched by combining glasses 1R and 2Y. This red would be designated as 1R + 2Y. These Lovibond glasses are used in a Lovibond Tintometer (Colorimeter) in which the glasses are placed in half the field of view and the color sample in the other half. One changes the glasses until a visual match is obtained. Logarithms to the base 10 are LOVIBOND COLORIMETER frequently used; for example, the log of 1,000 is 3 since 103 = 1,000. See LOVIBOND COLOR SYSTEM LONGITUDINAL CHROMATIC ABERRATION [4] LOVIBOND NUMBERS An aberration which affects the sharpness of all parts of an image because different colors come to a focus at different distances from the lens. Numbers proportional to the densities of three glass colorants (a yellow, a red, and a blue) required to modify a standard light source to produce a color match. A system based on the use of 3 sets of transparent glasses, red, blue, and yellow (actually magenta, cyan, Approved For Release 2003JON f l[ NTI*t8BO456OA007300010028-8 Approved For Release 2003/05(14FI1~I;RAPP.Z8BO456OA0073000100?Pc/R-o1/72 LOVIBOND TINTOMETER See LOVIBOND COLOR SYSTEM LUMEN The LUMINOUS FLUX per unit SOLID ANGLE from a point source whose intensity is one CANDELA. LUMINANCE The luminous intensity of any surface in a given direction per unit of projected area of the surface as viewed from that direction. Note: The unit is the candela per square meter. See Figure 4. The ratio of the LUMINANCE of a body to that of a perfect reflect- ing diffuser identically illu- minated. LUMINANCE PURITY See COLORIMETRIC PURITY LUMINESCENCE [8] Visible glow of certain substances when subjected to stimulation by electromagnetic radiation, electric fields, or heat. The general term luminescence also embraces phenomena such as electro- luminescence, fluorescence, and phosphorescence. A measure of the visibility or brightness-producing capacity of light consisting of the ratio of photometric quantity to correspond- ing radiometric quantity. The coefficients by which the COLOR-MIXTURE DATA for any color need be multiplied so that the sum of the three products is the LUMINANCE of the color. Note: For a single set of primaries and a single observer these coefficients are the same for all sample colors and may be interpreted as the luminosities of the primaries. For the CIE 1931 2? STANDARD OBSERVER and primaries, these coefficients are 0, 1, 0, all luminosity being associated with the tristimulus value Y. LUMINOSITY CURVE (PHOTOPIC CURVE, VISIBILITY CURVE, LUMINOSITY FUNCTION) Curve of the relative LUMINOSITY of the visual spectrum plotted as a function of wavelength. Note: In the figure below, the photopic luminosity curve of the human eye is presented. Approved For Release 2003A0?'NFJ D iA1SBO456OA007300010028-8 Approved For Release 20A31Q5, '{6EC,ItiwQP78B0456OA00730001 &87R_01/72 1.1 1.0 0.9 o 0.8 0.7 0.6 D.5 0) > 0.4 0.3 e -I 0.2 Wavelength, nm LUMINOSITY FACTOR (K) The Luminosity Factor for radiation of a particular wavelength is the ratio of the LUMINOUS FLUX at that wavelength to the corresponding RADIANT FLUX. It is expressed in lumens per watt. Note: K = Fx/4 where: F = LUMINOUS FLUX ~ = RADIANT FLUX X = WAVELENGTH LUMINOUS [5] Characteristic of the illuminant mode of appearance; glowing, having the appearance of emitting light. LUMINOUS DENSITY [5] Luminous energy contained in a unit volume of space. The LUMINOUS REFLECTANCE that a perfectly diffusing surface would have to possess in order to appear as bright as the object in question under the same illuminating and viewing conditions. The ratio of the LUMINANCE of the second surface of a light- transmitting specimen to the illuminance of the first surface. LUMINOUS EFFICIENCY [5] The Luminous Efficiency of RADIANT ENERGY is the ratio of the LUMINOUS FLUX to the RADIANT FLUX. Note: Luminous Efficiency is usually expressed in lumens per watt of radiant flux. It should not be confused with the term efficiency as applied to a practical source of light since the latter is based upon the power supplied to the source instead of the radiant flux from the source. For energy radiated at a single wavelength, Luminous Efficiency is synonymous with LUMINOSITY FACTOR. LUMINOUS EMITTANCE [5] The LUMINOUS FLUX being radiated from a unit area of a primary or secondary source (lumens per unit area). Approved For Release 20 B*. p78BO456OA007300010028-8 Approved For Release 2003/A /oj5 q q[j J8B0456OA00730001009-&/R-01/72 LUMINOUS ENERGY [5] Note: See Figure 4, and Table 1 in the Appendix. Evaluation of RADIANT ENERGY according to its stimulation of the brightness attribute of visual perception. The flow rate of LUMINOUS ENERGY expressed in LUMENS. Note: See Figure 4 in the Appendix. LUMINOUS INTENSITY [5] LUMINOUS FLUX emitted per unit solid angle about a source. The unit is the CANDELA. Note: See Figure 4 in the Appendix. LUMINOUS REFLECTANCE [5] Ratio of reflected to incident LUMINOUS FLUX. LUMINOUS TRANSMITTANCE [5] Ratio of transmitted to incident LUMINOUS FLUX. LUSTER [5] The appearance of a surface which results from its mirror-like reflection. A unit of ILLUMINANCE equivalent to one lumen of incident light per square meter. Approved For Release 2003 I DEWOAt8BO456OA007300010028-8 Approved For Release 20p ,(Q~ lbtRftl~ P78BO456OA00730001 8r?-01/72 Elliptical shaped figures on a CIE CHROMATICITY DIAGRAM joined by the locus of points that correspond to colors that are, visually, equally different from the color at the center of the ellipse. by stimulation of the normal human eye with a wavelength combination which is the approx- imate COMPLEMENT of 515 nanometers (or green). (2) The COMPLEMENT of GREEN. MAGENTA DYE Note: MacAdam Ellipses are equally different perceptually from the color (the dot) at the center. MACULA (MACULA LUTEA; MACULAR AREA; YELLOW SPOT) [5] A yellow pigmented area in the RETINA of irregular shape and variable from one individual to another. The FOVEA is found in the Macula. A container for rolled film or photographic plates attached to the camera body and usually equipped with automatic mechanisms that advance and position the photographic material for exposure. MAGENTA (MINUS-GREEN) (1) The purple hue attribute of vision sensations typically evoked During the processing of color films it is the red-blue dye formed in the green sensitive layer. Note: In positive transparencies it is formed where green wave- lengths were not imaged, thus stopping the transmission of green except where it was imaged. In negative transparencies it is formed where green wavelengths were imaged, thus allowing its complement (MAGENTA) to be transmitted. The bands perceived on either side of an edge between a light and dark area due to the brightness differ- ences. The bands are perceived parallel to the edge and on the light side the band is seen as lighter and on the dark side, darker. Note: Mach bands are often diffi- cult to see and may cause mis- judgment in choosing the position of an edge or its midpoint since it has been shown that people tend to choose closer to the dark band. Approved For Release 2O1 4H4):EW-MP78B04560A007300010028-8 Approved For Release 200tl DfN f9k1F78BO456OA00730001 O 2&,T/R-01 /72 MAERZ AND PAUL, DICTIONARY OF COLORS A dictionary containing 7056 different printed colors mixed from eight basic colors and seven gray pigments. The dictionary also contains 4000 color names for designating some of the printed colors. Essentially a mask is an image (black and white or single- colored) of the original to be copied which, when placed in both blue and green light, lightens both the blues and greens. regard- less of the color of light used to expose it, a single mask used in exposing all three color-separation negatives can accomplish no hue- shift correction. With two masks, however, it is possible to correct not only the relative brightness and saturation errors but also the most serious hue-shift errors. See COLOR MATCH; INVARIANT MATCH; CONDITIONAL MATCH registry with the original, affects MAXWELL TRIANGLE the final copy in some way. In color reproduction masks are used to improve color balance and fidelity by correcting brightness and saturation errors. Note: Practically speaking, the effect of a single mask is to lighten the reproduction of all colors complementary to the color of the filter used in making the mask. The mask also reduces the contrast of the original and thereby permits a higher printing contrast which increases the saturation of all colors. For example, a magenta filter absorbs green light and thus allows less exposure in the picture than it does through the other colors. When the mask has been developed and registered with the trans- parency, the greens are effectively lightened in relation to the other colors. Similarly, a mask exposed with a red filter, which absorbs The equilateral triangle in which the primaries are represented at the vertices and other colors that can be formed by the primaries fall in specific places in between. Note: In the figure below is an example. A color is calculated by determining the distance it falls from the sides opposite the apexes. Thus Color A may be calculated as 2 units of blue, 4 red, and 4 green. Approved For Release 20031b'3P1F41 PA R6P78BO456OA007300010028-8 Approved For Release 20M5MIq.,RQP78BO456OA00730001fP?@7q(_01/72 Intermediate in value or lightness; between light and dark. MEMORY COLOR [5] Color, as remembered, of an object, film, or illumination. The memory and other surfaces which possess the physical feature known as metallic reflection and which exhibits chromatic highlights similar in HUE to the surface as a whole. Metallic gold, silver, copper, bronze, chromium, and aluminum are examples. colors of an individual exert METAMERIC COLORS influence in the determination of the colors of the familiar objects which he perceives. Note: Memory of colors is not reliable. Generally memory colors emphasize dominant aspects of the true colors, e.g., reds are redder, dark-reds are darker and redder, etc. MERCURY HYPERSENSITIZING [4] A method of hypersensitizing (increasing the sensitivity) con- sisting of placing a globule of mercury in the film container. Colors which have different SPECTRAL DISTRIBUTIONS but appear to be identical colors under certain illuminants or to certain observers. Note: According to most experts, metameric colors should not appear on color transparencies. Any two metameric colors. The mercury vapor will penetrate The phenomenon in which two colors the film wrappings and exert its are perceived as matching hypersensitizing effect. Generally in spite of spectral differences. results in a greatly increased Also, the phenomenon of METAMERIC log e level. COLORS. MESOPIC VISION (TWILIGHT VISION) [5] METAMERISM, GEOMETRIC Vision intermediate between PHOTOPIC and SCOTOPIC VISION and consequently attributed to the combined functioning of the RODS and CONES. The phenomenon in which two colors are perceived as matching when observed at some sets of illumina- ting and viewing angles but not at other sets. METALLIC COLOR [5] Note: Generally due to differences between the color materials, e.g., Color typically evoked by selective texture, thickness, distribution of reflection from certain metallic colorants, etc. Approved For Release 20 f #Dl 78B04560A007300010028-8 Approved For Release 2003/Q Af~Q ffp7fB04560A00730001002 C/R-01/72 METAMERISM, INSTRUMENTAL The phenomenon in which two colors with different spectral curves have the same color coordinates when measured on one or more instruments but different coor- dinates when measured on other instruments. METER-CANDLE Same as LUX. METER-CANDLE-SECOND A unit of exposure in SENSITOMETRY; one second of exposure at a MICRON distance of one meter from a light source of one CANDELA. METER-LAMBERT (APOSTILB) A unit of LUMINANCE equal to 1 candela/meter2. 7T Note: See Table 1 in the Appendix. METHUIN COLOR ATLAS A collection of 1,266 printed colors arranged in orderly fashion with names for many of them. Not a highly systematic collection. In the United States, the REINHOLD COLOR ATLAS is the same. METRIC SYSTEM [4] See also: RAYLEIGH SCATTERING A system of weights and measures MILLIMETER (based on the decimal system) which is the international standard for scientific use. The meter, the liter, and the gram are the units of measures of length, capacity, and weight, respectively. MICRODENSITOMETER [4] A special form of DENSITOMETER for measuring densities in very small areas and used for measuring edge gradients on imagery and granularity of films. A unit of length in the metric system; the thousandth part of a millimeter or 10,000 Angstrom units. The standard abbreviation for micrometer is pm. Formerly called the MICRON. MICRO-RECIPROCAL DEGREE [5] Unit of RECIPROCAL COLOR TEMPERATURE obtained when one million is divided by the temperature in Kelvin. Abbre- viated mired or prd. The selective scattering of wave- lengths of light caused by parti- cles and molecules in the atmos- phere having approximately the same size as the wavelength of the incident light. A unit length; 1/1,000 of a meter; mm is the standard abbreviation for millimeter. Approved For Release 200316' ID O8BO456OA007300010028-8 Approved For Release 20e (QfibtWt, pP78BO456OA00730001RP8r~_01/72 MIL 1/1,000 of an inch. MILLIMICRON Obsolete term for NANOMETER. MINUS-BLUE FILTER A yellow filter which will not transmit blue wavelengths. Note: Generally used over an aerial camera lens to reduce the transmission of predominant blue wavelengths caused by ATMOSPHERIC SCATTERING. transmission of the blue wave- lengths and thus reduce the effect on the imagery. MIXTURE, LIGHT Superimposition of two or more lights. Characterization of a color according to whether it is perceived to belong to an aperture, a surface, a volume, an illuminant, etc. Note: Color transparencies are said to have "Film Color" as a MODE OF APPEARANCE. MINUS COLOR MONOCHROMATIC [4] A COMPLEMENTARY color. For example, (1) Containing light of one color. minus-blue is complementary to blue. (2) A scene composed of nearly Note: A Minus-color filter is one the same color. which will not allow that color to pass through. Thus, a yellow (3) Containing light of a single filter is a minus-blue filter WAVELENGTH. because blue is not transmitted. From above definitions, yellow or MONOCHROMATIC VISION minus-blue is complementary to blue. Vision in which no HUES or MIST SATURATIONS are seen. Only brightness differences are Particles of water vapor suspended perceived. The individuals are in the atmosphere. These particles called Monochromats. tend to scatter blue light more than red light. The result is MONOCHROMATOR called ATMOSPHERIC SCATTERING and causes a bluish-cast on high- A device that can be used to altitude imagery. separate or select a single wave- length from any portion of the Note: HAZE FILTERS (MINUS-BLUE SPECTRUM of the source. FILTERS) are used over aerial camera lenses to reduce the Approved For Release 20c OP 4DP#t78BO456OA007300010028-8 Approved For Release 2003/M IMNRP7,8B04560A0073000100MC/R-01 /72 Vision resulting when using only one eye. MULTILAYER FILM (Continued) double-coated films for reduction of HALATION effects and 2- or 3-layer films for color photog- raphy. A fringe of color occurring at the MULTISPECTRAL PHOTOGRAPHY edge of moving images when the (SPECTRAZONAL) ADDITIVE COLOR SEPARATIONS are taken at different instants in time. MOTTLED [5] Unevenly colored; variegated; mealy, spotted. MOTTLING [4] Marks in the form of density variation which often appear on negatives or prints caused by insufficient agitation of the developer. MULTIDIRECTIONAL ILLUMINATION [5] The simultaneous imaging of several SPECTRAL BANDS; each band on a separate film or emulsion layer. Note: Generally, several (up to nine have been noted) cameras are mounted on the same platform, each with a panchromatic film and each with a different filter. Each film will then image a different range of wavelengths of the same scene. Color films are in a sense Multispectral because each emulsion layer is sensitive to a different range of wavelengths. Multidirectional illumination on MUNSELL BOOK NOTATION a surface is produced by several separated light sources of a relatively small area. It is characterized by the fact that a small opaque object placed near the illuminated surface casts several shadows. Munsell color notation as applied to the hue, value, and chroma scales of the samples of the MUNSELL BOOK OF COLOR. Currently, Munsell Book Notation is identical with MUNSELL RENOTATION but this was not true before 1943. A film coated with two or more layers of emulsion of differing characteristics; these include Collections (matte and glossy) with an orderly arrangement of a series of colored chips. It is three-dimensional in nature with the vertical axis Approved For Release 20031@NFI B A$BO456OA007300010028-8 Approved For Release 20~bWkibt~?,RQP78BO456OA007300019PJ@7k_01/72 representing black to white (10 shades) and called VALUE; the radial axis represents increasing amounts of color from the center outward and is called CHROMA; colors of the different HUES (40 are represented) surround the vertical axis. The book contains about 1,000 color samples (both CHROMATIC MUNSELL COLOR SYSTEM (Continued) for the samples of the MUNSELL BOOK OF COLOR. The Munsell Color System, however, is a notation system which is and can be used independent of any set of samples. and ACHROMATIC); each adjacent sample MUNSELL HUE being as perceptually different as the next adjacent sample. Each sample color is specified by a letter-number system of notation with respect to MUNSELL HUE, MUNSELL VALUE, AND MUNSELL CHROMA. MUNSELL CHROMA [5] (1) Expression of the degree of departure of an object color from the ACHROMATIC color of the same lightness or Munsell Value. (2) Analogous to Saturation. Note: The Munsell Chroma scales have approximately uniform perceptual steps; under ordinary observing conditions Munsell Chroma of a specimen correlates well with the saturation of the color perceived to belong to the specimen. See also: MUNSELL HUE; MUNSELL VALUE The coordinate system comprising MUNSELL HUE, VALUE, and CHROMA. It is three-dimensional in nature and is often arranged as described HUE in the Munsell Color System. See HUE. Color specification in terms of MUNSELL HUE, MUNSELL VALUE, and MUNSELL CHROMA, written in the form of H V/C, e.g., 5R 4/10. Munsell color notation applied to HUE, VALUE, and CHROMA scales in accordance with the recom- mendations made in 1943 of the OSA Subcommittee (of the Colorimetry Committee) on the Spacing of the Munsell Colors. The original notations by Munsell were changed to more nearly reflect perceptual differences. MUNSELL VALUE [5] (1) Expression of the LUMINOUS REFLECTANCE of an object color on a scale giving approximately uniform perceptual steps under usual conditions of obser- vation. (2) Analogous to Lightness Approved For Release 20Q@IWFo 1*p78BO456OA007300010028-8 Approved For Release 2003eO( I K[8BO456OA00730001009?1Q/R-01 /72 Note: Munsell Value of an opaque surface may be found approximately by taking the cube root of the LUMINOUS REFLECTANCE according to the equation V = 25 Y1/3-17 where V is Munsell Value and Y is luminous reflectance expressed on a scale so that Y = 100 for white. Under usual conditions. of observation, the Munsell value of a specimen correlates closely with the lightness of the color perceived to belong to the specimen. Approved For Release 2OO ON L kbk8BO456OA007300010028-8 Approved For Release 2~"/i1dE f f P78B0456OA0073000 Z'- o 1 /72 NADIR 14] PHOTOGRAPHIC NADIR (PHOTO- GRAMMETRY): the point at which a vertical line through the perspective center of the camera lens strikes the plane, of the photograph. Also referred to as the nadir point. GROUND NADIR: the point on the ground vertically beneath the perspective center of the camera lens. MAP NADIR: the map position for the ground nadir. NAGEL ANOMALOSCOPE [18] Color vision test in which the observer determines relative amounts of red and green necessary to match spectral yellow. NANOMETER (nm) A unit of length in the metric system; the billionth (10-9) part of a meter, or thousandth part of a micrometer, or 10 angstroms. Formerly called the millimicron. Customarily used to express the wavelength of visible light, e.g., 400-700 nm. NEUTRAL DENSITY FILTER See FILTER, NEUTRAL DENSITY. NEGATIVE A photographic image on film, plate, or paper, in which the ACHROMATIC or CHROMATIC colors to which the emulsion is sensitive are reversed or COMPLEMENTARY, respectively. NEGATIVE COMPONENT IN COLOR MIXTURE [18] Component or primary color that is mixed with the sample light in order to change it sufficiently to obtain a match with a mixture of the other two components (or primaries). NEW LONDON NAVY LANTERN TEST [6] A test of color vision used to screen out the more severe DICHROMATIC defective (red-green color defects). It uses back- lighted red, green, and neutral filters in pairs. The individual is asked to simply name the colors of the pairs. The test lights seen are very small simulating distant signal lights. An ACHROMATIC COLOR falling between black and white; a gray. A strip of different NEUTRAL DENSITY FILTERS in discrete steps or continuous tones. NM (NANOMETER) See NANOMETER (nm) Approved For Release 2O1 a ET P78BO456OA007300010028-8 Approved For Release 2003/,0,5jjJ4% 6bLj 8B0456OA00730001009?1/R_01/72 NODAL POINT [4] (2) Free of visual defects. One of two points on the OPTICAL Note: In the Figure below, line A AXIS of a lens (or a system of is the normal to the surface. lenses) such that, when all object distances are measured from one point and all image distances are measured from the other. Note: In the Figure below, the ray emergent from the second point (N") is parallel to the ray incident at the first (N). The first nodal point (N) is also referred to as NORMAL COLOR VISION the front nodal point or incident nodal point and the second point See NORMAL TRICHROMATIC VISION (N") as the rear nodal point or emergent nodal point. Also called NORMAL TRICHROMATIC VISION (NORMAL "node", front node, or rear node. TRICHROMAT) a Posse meaning normal color vision. The term trichromatic means here that the normal observer needs 3 primary colors (blue, green, and red) to mix and match all the colors he can perceive. NODAL PLANE [4] The plane perpendicular to the optical axis at a NODAL POINT. NONCURLING [4] A term applied to film which has a clear gelatin coating on the back to minimize curl caused by shrink- age of the emulsion in drying. NORMAL [5] (1) In optics, the perpendicular to a surface at the point where a ray of light is incident upon a surface. NON-SELECTIVE FILTER See FILTER, NEUTRAL DENSITY NON-SPECTRAL COLORS (1) Colors not found in the SPECTRUM. (2) Mixtures of 2 or more wave- lengths of light. Purple is an example as it represents a mixture of red and blue light. Approved For Release 2003EWI[EFTtk8B0456OA007300010028-8 Approved For Release 20Q (Q ibEWf IW P78BO456OA00730001 ff&8yW-01 /72 OBJECT COLOR [5] Color seen as belonging to an object. This includes surface and volume colors to the extent that surfaces and volumes are perceived as_objects or parts of objects. Note: In a strict sense, it is not legitimate to attribute a color to an object but only to the light emanating from it as perceived by an observer. The capacity of an object to modify the color of the light incident upon it corresponds to the common concept of the color of the object. Object colors are relatively insensitive to changes in viewing conditions, viz., they exhibit the phenomenon of COLOR CONSTANCY. In addition, objects tend to be related to particular colors, e.g., red apples, blue violets, etc. Thus the perception of an object's color may be influenced by previous experience with the object. OBJECT-COLOR PERCEPTION [5] Color perceived as belonging to a non-self-luminous object. See Also: OBJECT COLOR OBLIQUE PHOTOGRAPH [4] A photograph taken with the camera axis intentionally directed between the horizontal and the vertical. High-oblique photograph: an oblique photograph in which the apparent horizon is included within the field-of-view; low oblique does not include the horizon. The phenomenon in which observers differ in their judgment as to whether METAMERIC COLORS do or do not match. - Areas located on both sides of the rear portion of the brain which are the anatomical-end of the OPTIC NERVES. The dominance of the perceptions of one eye over the other. Note: When viewing two colors, one with each eye, one color may dominate in the field of view because of OCULAR DOMINANCE. OLIVE [5] Any color which manifests a hue predominantly similar to that of olive, dark-greenish yellow, a mixture of yellow, green, and black. (The complement of bluish-purple). Approved For Release 2O IPM) 78BO456OA007300010028-8 Approved For Release 2003t(y4 [8BO456OA00730001009?*/R-o1/72 (1) The degree of obstruction to the transmission of visible light. (2) Ratio of the measured reflec- tance of the sample to the reflec- Note: See Figure 1 in the Appendix. Generally, people are not aware of this blind area because the eyes continually move and one eye sees the area blind to the other. tance measured with the sample over OPTIC NERVE a white background, the white back- ground having a reflectance of 89%. A bundle of elongated axons of the GANGLION CELLS which passes the visual information to the GENICULATE BODY. Any doctrine to the effect that color vision can be explained on OPTIC RADIATIONS the basis of three pairs of opposing colors such as a red Nerves which carry the visual whose negative is green, a blue information from the GENICULATE whose negative is yellow, and BODY to the OCCIPITAL CORTEX. a white whose negative is black. See Also: HERING COLOR THEORY; HURVICH-JAMESON COLOR THEORY The neural junction where the two OPTIC NERVES join and then separate. It is at this point where all nerve fibers from the right half of both retinas (left field of vision) join, leave the chiasm, and go to the left GENICULATE BODY while the nerves of the left half of both retinas (right field of vision) join and go to the right GENICULATE BODY. The term for the two OPTIC NERVES after they have left the OPTIC CHIASMA. They differ from the nerves in that each contains information from half (left or right) the field-of-view. OPTICAL AXIS (PRINCIPAL AXIS) [4] In a lens element, the straight line which passes through the centers of curvature of the lens surfaces. In an optical system, the line formed by the coinciding principal axes of the series of optical elements. OPTIC DISC (BLIND SPOT) OPTICAL CENTER [4] An area of the Retina where the optic nerve is formed and leaves the retina. Contains neither rods nor cones and thus is a true blind area of the retina. The point, usually within a lens, at which the light rays are assumed to cross. Approved For Release 2003N4I Itk8B04560A007300010028-8 Approved For Release 20N5MENtiF;QP78BO456OA007300019p??A-01/72 OPTICAL DENSITY (D) The logarithm of the reciprocal of the TRANSMITTANCE of a medium. See Also: ABSORBANCE OPTICAL SCATTERING See SCATTERING OPTICAL WEDGE A device consisting of a strip of material--glass, celluloid or plastic--covered with a pigment or developed silver emulsion layer which is clear at one end and gradually becomes opaque towards the other. The transition from transparent to opaque may take place smoothly (continuous wedge) or in regular steps, in which case it is called a STEP WEDGE. Note: Generally used as a comparison device in determining the DENSITY or OPACITY of a transparent area. ORA SERRATA [6] A thin irregular margin of the RETINA that represents the anatomical limit of the receptor system. Note: See Figure 1 in the Appendix. The hue attribute of visual sensations typically evoked by stimulation of the normal retina with radiation of wavelengths of approximately 592 nanometers. ORTHOCHROMATIC [5] (1) Characterizing the equivalence between the photographic effect of various colors upon a photographic material and the physiological effect upon the eye. (2) By old usage, characterizing a photographic material sensitive to all colors except red. ORTHOCHROMATIC EMULSION [5] A photographic emulsion which is sensitive to yellow, green, blue, and shorter wavelengths, but not to orange or red. ORTHOPANCHROMATIC [8] Term used to describe materials sensitized to all colors of the visible spectrum that have an evenly balanced red sensitivity. In this they differ from the excessive red sensitivity of some high-speed panchromatic emulsions which are produced to give speed as a first consideration. Approved For Release 20 IFtD J*p78BO456OA007300010028-8 Approved For Release 2003IMJf r:l b 9 [8B0456OA0073000100 /R-01 /72 A color system used to designate colors by their COLOR CONTENT; WHITE CONTENT, and BLACK CONTENT. Also based on the concept that color content + white content + black content = 1. There are 24 HUES. Each hue is described by 36 shades (colors) developed by adding white and black (called shading or toning) to the HUE. Each hue and its 36 shades are described on an OSTWALD COLOR TRIANGLE. (There are 24 such tri- angles, one for each hue). The arrangement of colors of constant OSTWALD HUE in a triangle showing the Hue's FULL COLOR CONTENT, WHITE CONTENT, AND BLACK CONTENT. There are 24 such triangles. Note: The Figure below shows an Ostwald Color Triangle. Black Analygous to saturation OSTWALD COLORS [5] A series of several hundred CHROMATIC and ACHROMATIC samples, each corresponding to a certain theoretical pigment combination of FULL COLOR CONTENT, WHITE CONTENT, and BLACK CONTENT; designated by a letter-number system of notation. Note: The most widely known collection based approximately on the OSTWALD COLOR SYSTEM is the Color Harmony Manual. See Also: OSTWALD COLOR SYSTEM: OSTWALD NOTATION OSTWALD HUE [5] Designation of DOMINANT WAVELENGTH or HUE by arbitrary numbers ranging from 1 to 24. Colors are designated by numbers and letters. The 24 Hues are numbered from 1 to 24. Each of the 36 shades are designated by 2 letters, each letter designating WHITE CONTENT and BLACK CONTENT of the shades. The theoretical color which contains neither black nor white. Mixtures of a SEMICHROME with black. Approved For Release 2003 1 DEW6At8BO456OA007300010028-8 Approved For Release 20Q, /~1 I~RnP78B04560A00730001 j8R-01/72 Mixtures of a SEMICHROME with white. OVERCAST SKY See SKY, OVERCAST OVERDEVELOPMENT [4] Result of leaving film or paper in the DEVELOPER too long, resulting in excessive density and contrast. Development continued beyond the time necessary to produce normal density and contrast. OVEREXPOSURE [4] Excessive duration of the interval in which light is allowed to act on a sensitive surface in making either a negative, positive, or a print. Note: Overexposure results in excessive density, a shortened tonal scale, and lack of detail. In REVERSAL COLOR FILMS it results in very desaturated, washed-out colors and detail is lost. OVERLAP [4] The amount by which one photograph covers the same area as covered by another, customarily expressed as a percentage. The overlap between aerial photographs in the same flight is called the end lap and the overlap between photographs in adjacent parallel flights is called the side lap. Approved For Release 20c6@Nf4DEUT* At78BO456OA007300010028-8 Approved For Release 2003f9i ff 16 R18B0456OA007300010090*/R-o 1 /72 PANCHROMATIC PERCEPTION,. COLOR SENSITIZED MATERIALS with a See COLOR PERCEPTION response to all colors of the visible spectrum. PERIMETER .PARABOLA [4] A device used in PERIMETRY Con- sisting of a semicircular arm A parabola is the curve formed by which can rotate about an axis a point in a plane so that its perpendicular to the visual distance from a fixed line of the plane. Colored stimuli can be plane and its distance from a fixed attached at the end of the arm point of the plane, not on the and moved towards the center. line, are equal. The importance The observer stares at the center of a parabola lies in the fact of the arm and is asked to name that parabolic reflectors will the color when he first perceives focus a parallel beam of light to it in his peripheral vision. a point and vice versa. Note: In the Figure below is a PERIMETRY parabolic reflector. All reflected light is focused at a point and The mapping of the COLOR ZONES vice versa. (the extent colors are perceived by the RETINA from the FOVEA outward) of the retina using a PERIMETER. The region of the retina remote from the center of vision. Generally, the area of the retina least sensitive to colors. Vision resulting from light falling on an area of the RETINA pH [4] immediately surrounding the FOVEA. A symbol expressing the degree Note: Color vision can be of acidity or alkalinity of a considered Paracentral Vision solution. It is equal to the since most of the CONES are found logarithm of the reciprocal of in this zone. the hydrogen ion concentration Approved For Release 2003NFID NN k8B04560A007300010028-8 Approved For Release 200ed&f.fD fRC78BO456OA0073000l Q PR-01 /72 pH [4] (continued) (LOG10 1/H). A neutral solution (pure water) has a pH of 7.0 while alkaline solutions have a higher pH and acid solutions a lower pH. For example, photographic developers are alkaline and have pH's with 8-11 range. PHOT [4] A unit of ILLUMINANCE equal to 1 lumen/square centimeter. PHOTOELECTRIC COLORIMETER [5] A photoelectric instrument using three or four photodetector- filter combinations to produce color coordinates easily transformed into approximate CIE tristimulus values. Note: It has not yet been found possible to build a perfectly accurate photoelectric colorimeter, but there are many useful approximations. Note: See Table 1 in the Appendix.PHOTOEMISSIVE DETECTOR PHOTOCONDUCTIVE DETECTOR [5] A detector of RADIANT ENERGY depending on change of its elec- trical resistance when irradiated. Note: Best known photoconductive detectors are the cadimium sulfide or lead sulfide cells requiring an external source of potential. The intensity interval between that at which light is just sensed and that at which it is seen as a color. During this interval light has neither HUE nor SATURATION. Detector of RADIANT ENERGY depending'on the emission of electrons when irradiated. Note: Photoemissive Detectors are commonly known as phototubes or photomultiplier tubes. An instrument used in PHOTOMETRY which measures LUMINANCE (the intensity of ILLUMINANCE). The Equality-of-Brightness Photometer employs simultaneous comparison of the sample to be measured and the standard. The Flicker Photometer presents the sample and standard to be compared, successively in the same visual area. The light intensity threshold at which HUE is just perceived. Usually the first Hues to be perceived are those corresponding to wavelengths of 620 nm and above. The measurement of LIGHT or the matching of brightness levels. Note: Photometry plays an Approved For Release 200(1 DCIj 78BO456OA007300010028-8 Approved For Release 200:f1pIDEN- 78B04560A00730001O - /R-01/72 PHOTOMETRY (Continued) important part in SENSITOMETRY . i.e., the study of the effect of varying exposure on photographic emulsion. PHOTOSENSITIVE [4] A term used to describe substances whose chemical compositions are altered by exposure to light. Note: The chemicals used in film emulsions are Photosensitive. PHOTON [5] PHOTOPIC VISION (DAYLIGHT VISION) Vision as it occurs when the eye is LIGHT-ADAPTED and can fully discriminate all colors. Note: Believed to depend upon the functioning of the retinal CONES instead of the RODS alone. See Also: LUMINOSITY CURVE PHOTORECEPTORS (RODS; CONES) A general term referring to both the RODS and CONES. PHOTOVOLTAIC DETECTOR (1) In quantum theory, the photon Detector of RADIANT ENERGY is the smallest unit of radiant generating a potential or voltage energy. when irradiated. (2) An obsolete unit of visual Note: The most common stimulation defined as that Photovoltaic Detector is the illumination upon the retina which selenium or barrier layer cell. results when a surface brightness of 1 candela per square meter is PHYSICAL DEVELOPMENT seen through a pupil of 1 square millimeter area. The development of the latent image by deposition upon it of Note: The term TROLAND is now used silver contained in the instead of Photon when referring developing solution itself to units of visual stimulation. instead of making use, as in See ADAPTATION, LIGHT; LIGHT- ADAPTED EYE the more usual chemical development, of the silver already present in the emulsion. The name attached to a COLORANT when it is used in a binder such as paint. Approved For Release 20001hI D&IN-HI78BO456OA007300010028-8 Approved For Release 20 th P78BO456OA0073000100:t -01 /72 The outer layer of the RETINA PLANCKIAN LOCUS where the light sensitive ends of the RODS and CONES lie. Locus of points on a PINK CHROMATICITY DIAGRAM representing the CHROMATICITIES of blackbodies at various A very light red, reddish-orange, temperatures. or reddish-purple. PITCH [4] Note: See Figure 2 in the Appendix. (1) Air Navigation: A rotation of PLANCKIAN RADIATOR an aircraft about the horizontal axis normal to its longitudinal Any radiator having the axis so as to cause a nose-up or CHROMATICITY and SPECIAL POWER nose-down attitude. DISTRIBUTION of a BLACKBODY. (2) Photogrammetry: A rotation of POINT SOURCE OF LIGHT the camera or platform about either the Y photograph axis or the exterior Y axis; tip or longitudinal tilt. In some photogrammetric instruments and in analytical applications, the symbol phi (~) may be used. Note: Pitch causes smearing or streaking in direction of flight to occur on the image. PLANCK'S LAW [5] The spectral emittance (WX) of a blackbody can be expressed as follows: WX = 211c 2 hX-5 (ehc/akT-l)-1 where c = speed of light h = Planck's constant X = wavelength T = absolute temperature A theoretical source of light whose size may be defined as being that of a "point". Note: A point source of light is a practical impossibility, but the mathematical processes of optics are greatly simplified by making calculations for light rays proceeding from a mathematical point. The act or process of filtering light in such a way that the vibrations are restricted to a single plane. Note: According to the wave theory, unpolarized light vibrates in all planes perpendicular to the direction of propagation. On passing Approved For Release 20 IKJD 78BO456OA007300010028-8 Approved For Release 200 ON N D 4qf 78BO456OA007300010% R-01/72 POLARIZATION (Continued) through or contacting a polarizing medium (such as Polaroid or a Kerr cell), ordinary light becomes plane-polarized; that is, its vibrations are limited to a single plane. A filter which passes light waves vibrating in one direction only. Used over the camera lens to cut down or remove polarized rays where they may constitute objectionable reflections from glass, water, or other highly reflecting surfaces. A system of SURFACE COLORS based on the mixture of known proportions of PIGMENTS. red; or violet, green, and red) from which most other colors may be produced by ADDITIVE SYNTHESIS. (2) The colors (cyan, magenta and yellow) from which most other colors may be produced by the SUBTRACTIVE COLOR PROCESS. Note: There is nothing absolute about primary colors. The above have been selected because more colors can be reproduced by mixing these colors than any other three colors. See Also: PSYCHOLOGICAL PRIMARIES A body or object emitting light by virtue of a transformation of energy into RADIANT ENERGY within itself. A photograph having approximately PRIMARY LUMINOUS STANDARD [51 the same rendition of tones or colors as the original subject, A light source by which the unit i.e., light for light and dark for of light is established and dark. from which the values of other standards are derived. Note: A positive may be copied from an original negative or processed directly using the REVERSAL PROCESS and REVERSAL FILMS. PRIMARY COLOR(S) (PRIMARY HUES; PRIMARIES) PRINCIPAL AXIS See OPTICAL AXIS PRINCIPAL FOCAL POINT See FOCAL POINT (1) The colors (blue, green, and Approved For Release 20 cGQNF DENTF b78BO456OA007300010028-8 Approved For Release 20fflaft Er 78B04560A00730001AP?@ -01/72 PRINCIPAL HUES respect to each other. In the terminology used in the Note: Prisms are sometimes used Munsell Color System, the to disperse light into bands of Principal Hues are the five hues colors. These colors are called from which the complete hue PRISMATIC COLORS. circuit is derived. They are red, yellow, green, blue, and purple. PRISMATIC COLORS PRINCIPAL PLANES [5] A term applied to the seven simple colors (violet, indigo, The planes perpendicular to the blue, green, yellow, orange, and optical axis in which lie the red) which result from passing nodal points of a lens. a ray of white light through a prism. See Also: NODAL POINTS; NODAL PLANE PRISMATIC SPECTRUM PRINCIPAL POINTS [5] The spectrum of colors formed by a PRISM. For lenses used in air, the same as the NODAL POINTS. See Also: PRISMATIC COLORS The densities measured to indicate The chemical treatment of exposed the effect a negative or film to form a permanent visible transparency will have when used image from the LATENT IMAGE. with a particular printer and print material. These PROTANOMALOUS VISION (PROTANOMALY; measurements must be A PROTAN) representative of the response of the material and exposing source. A form of the defective color vision called ANOMALOUS Note: For color printing the TRICHROMATISM.in which more red Printing Density of each dye is required in a mixture of red layer should be determined for and green to match a yellow than proper exposure of all layers. in the case of the normal trichromat. The relative visual PRISM sensitivity is less than normal in the red, orange, and yellow An optical solid made of glass, regions of the spectrum. Hue quartz, or other transparent discrimination is poor in the red material with at least two polished to green region of the spectrum. plane surfaces, inclined with Approved For Release 20cQ(DNf4DPI1 t78BO456OA007300010028-8 Approved For Release 200t'UNPIbyA f L78BO456OA007300010 SR-01/72 PROTANOMALOUS VISION (PROTANOMALY; A PROTAN) (Continued) Note: In the population an estimated 1.0% of males and .02% of females are affected [6]. PROTANOPIA (A PROTANOPE) A form of the defective color vision called DICHROMATISM in which the relative spectral visual sensitivity is much less than the normal in the red, orange, and yellow regions of the spectrum and in which colors can be matched by a mixture of yellow and blue stimuli. The eye is less sensitive than normal or "blind" to reds; therefore, reds and their Note: There are a number of color vision tests which use these plates including the American Optical Company Hardy-Rand- Rittler Pseudo-Isochromatic Plates, Ishihara, Dvorine, Bostrom, and Rabkin. The four psychologically simple or unique hues of NORMAL color perception (blue, green, yellow, and red). The HUES are perceived as being unique in the visual spectrum: thus the red is neither bluish nor yellowish nor greenish; the yellow is neither reddish nor greenish nor bluish; etc. COMPLEMENTS, blue-greens, are seen PUPIL as gray. A Protanope's colors can be matched with mixtures of yellow and blue. Note: In the population an estimated 1.0% of males and .02% of females are affected [6]. The aperture through which light is admitted to the retina. It changes in diameter (2 to 8 millimeters) with variations in luminance. Note: See Figure 1 in the PSEUDOSCOPIC IMAGE appendix. An image in which the normal impression of stereo relief is reversed. PUPIL, ENTRANCE PSEUDO-ISOCHROMATIC CHARTS OR PLATES PUPIL, EXIT Charts for testing color See EXIT PUPIL deficiency comprised of colored, spots or dots which yield a PUPILLA recognizable pattern (number, letter, irregular line) to a See OPTIC DISC normal observer but yield a different or non-recognizable pattern to an abnormal observer. Approved For Release 200?'H DERT4Ak78BO456OA007300010028-8 Approved For Release 20MOV,D: gP78B04560A00730001RPffA_O1/72 See COLORIMETRIC PURITY; EXCITATION PURITY (1) The JUST NOTICEABLE DIFFERENCE in PURITY. Note: In the Figure below is shown the JNDs in purity of wavelengths (a) 440 nm, (b) 490 nm, (c) 540 nm, and (d) 640 nm. 16 14 12 n 5 10 8 6 4 2 100 80 60 40 20 0 Percent purity (2) The JUST NOTICEABLE DIFFERENCE between white and a spectral color. Note: In the Figure below is shown the JND steps from white for the spectrum in Nanometers. _y= ~~, PURE COLOR [5] Any color which, like the SPECTRUM COLORS, approaches the condition required for maximum saturation; free of added mixtures of black and white. PURKINJE AFTER-IMAGE See AFTER-IMAGE, PURKINJE PURKINJE PHENOMENON (PURKINJE SHIFT) As brightness is decreased, the blue and green wavelengths do not darken as fast as red and orange wavelengths. The phenomenon is related to the shift in retinal sensitivity during the transition from PHOTOPIC (cone) to SCOTOPIC (rod) VISION. (1) A series of distinctive reddish-blue hues which are caused by combinations or mixtures of long (red) and short (blue) wavelengths of light and are not produced by any single wavelength. (2) The COMPLEMENT of yellow- green (~560 nm). (3) In the CIE COLOR SYSTEM, Purples lie in the region bounded by the straight line connecting the blue end of the spectrum with the red end and the straight lines from the achromatic point to the red and blue ends of the spectrum. See Figure 2 in the Appendix. Approved For Release 20 I*E DE 1i 78BO456OA007300010028-8 Approved For Release 200 /A 1ADGl l[ 78B04560A007300010R3MR_01/72 In the CIE CHROMATICITY DIAGRAM it is the straight line connecting the ends of the SPECTRUM LOCUS. Note: See Figure 2 in the Appendix. Approved For Release 20 (GQNf4D KTI b78BO456OA007300010028-8 Approved For Release 20q, (wFiDtt iIWQP78BO456OA00730001RP?PA_01/72 Q-FACTOR See CALLIER QUOTIENTS QUART In liquid measure, equal to 2 pints or 32 fluid ounces. Metric equivalent 0.946 liters. A camera lens made of quartz rather than glass. Transmits ultraviolet rays for special photography. Approved For Release 20 1*14DI*b78BO456OA007300010028-8 Approved For Release 200W6DMQF 78BO456OA007300010RV/R_01 /72 A test for defective color vision which, in part, uses PSEUDO-ISO- CHROMATIC PLATES. The amount of RADIANT FLUX per unit SOLID ANGLE and unit projected area of surface of the light source. The RADIANT POWER emitted per unit SOLID ANGLE in a specified direction. Note: The unit is The Watt/ Steradian. RADIANT POWER See RADIANT FLUX RADIANT REFLECTANCE [5] The ratio of the RADIANCE of the body to that of a perfect reflecting diffuser identically irradiated. RADIANT ENERGY [5] Energy traveling through space in the form of ELECTROMAGNETIC WAVES of various lengths. Note: Usually measured in units of energy such as ergs, joules, calories, or kilowatt hours. The flow rate of radiant energy. It is expressed preferably in watts or in ergs per second. Ratio of reflected to incident RADIANT FLUX RADIANT TRANSMITTANCE [5] Ratio of transmitted to incident RADIANT FLUX RADIATION [20] Emission on transfer of energy in the form of ELECTROMAGNETIC WAVES. An emitter of radiant energy. RADIATOR, COMPLETE; RADIATOR, FULL; RADIATOR, IDEAL All synonyms for BLACKBODY. RADIANT FLUX DENSITY [20] The ratio of RADIANT FLUX at an element of surface to the area of that element. RADIANT INTENSITY [20] RATIOMETER [5] Any device used to test the ACTINIC equality of differently colored lights transmitted to the photographic material in making COLOR SEPARATION NEGATIVES. Approved For Release 206QNFAD III 78BO456OA007300010028-8 Approved For Release 20Q (QSLit tt t1RQP78BO456OA007300019P J@A-01 /72 D AL RAY, EMERGENT A ray of light leaving a medium. RAY, INCIDENT A ray of light falling on or striking a surface. RAY OF LIGHT [12] The geometrical concept of a single element of light propagating in a straight line and of infinitesimal cross section; used in analytically tracing the path of light through an optical system. A trigonometric calculation of the path of a light ray through an optical system. RAYS, MARGINAL imagery the Rayleigh Scattering by the atmosphere causes imagery to have a bluish overcast. In addition, moist, humid air will scatter more than dry, arid air. Thus imagery collected over deserts suffers less from Rayleigh Scattering. A rgciprocal of COLOR TEMPERATURE (10 /T) usually expressed in MICRORECIPROCAL DEGREE (abbreviated mired, or bird). Note: Reciprocal color temperature provides a more uniform chromaticity scale than does color temperature itself: a given small interval in Reciprocal Color Temperature is approximately equally perceptible as a difference in CHROMATICITY, regardless of color temperature. For example a difference of 100 K at 20,000 K is about as The rays of light passing through perceptible as a difference in an optical system near the edge of chromaticity as 10 K at 2000 K. the APERTURE. RECIPROCITY FAILURE (RECIPROCITY RAYLEIGH SCATTERING EFFECT) [4] The scattering of light by Photographic materials do not particles or molecules whose size , attain the same density from an is smaller than the wavelength of exposure by a high-intensity the ray of light being scattered. light source acting for a short The intensity of the scattered light is inversly proportional to the 4th power of the wavelength. Thus, short wavelengths (blue) are scattered to a greater extent than long wavelengths (red). Note: On high-altitude color time as from an exposure by a low-intensity light source acting for a longer time, even though the product of time and intensity is the same in both cases. For example, when the intensity of the light is doubled, halving the exposure time does not result in Approved For Release 20o6jgNf3DEbkTMk78BO456OA007300010028-8 Approved For Release 200 / 'Mb M fdl 78BO456OA0073000109??4R-01/72 RECIPROCITY FAILURE (RECIPROCITY EFFECT) [4] (Continued) exactly the same DENSITY. This is called Reciprocity Failure. It is present to some degree in all photographic materials. RECIPROCITY LAW (BUNSEN-ROSCOE LAW) The density obtained on an emulsion is primarily a function of EXPOSURE independent of the actual light intensity or time considered separately. Note: This law does not hold strictly for any emulsion and some deviate considerably from the law. This deviation is called RECIPROCITY FAILURE. An instrument used to provide a graph of the SPECTRAL REFLECTANCE of opaque samples or the SPECTRAL TRANSMITTANCE of transparent samples, as a function of the wavelength. RECURRENT VISION [5] A succession of POSITIVE and NEGATIVE AFTERIMAGES or after- sensations. See Also: AFTER-IMAGE RED (1) The hue attribute of visual sensations typically evoked by stimulation of the normal human eye with radiation of wavelengths approximately 630 nm. (2) Any hue predominantly similar to that of the typical red. (3) The COMPLEMENT of Blue- green (521 nm). RED BLINDNESS See Protanopia RED-GREEN BLINDNESS A common form of partial color-blindness or DICHROMATISM in which red and green stimuli are confused because they are seen as various saturations and brightnesses of yellow, blue, or gray. See Also: PROTANOPIA: DEUTERANOPIA RED-SIGHTED See ERYTHROPSIA REFLECTANCE The ratio of the reflected RADIANT or LUMINOUS FLUX to the INCIDENT FLUX. Color seen as reflected from a perceived object. Approved For Release 20O DEIRTAIM78BO456OA007300010028-8 Approved For Release 20 Q. Vbt W78B04560A00730001AD?@t-01/72 REFLECTED LIGHT Reflectivity at a specified wavelength. Rays of INCIDENT light turned back or "rebounded" from a surface. REFLECTOR REFLECTION A reflector is a device which is used to redirect light by Light rays being returned from a reflection in a desired direction surface. or directions. REFLECTION, ANGLE OF [4] REFRACTING PRISM [4] The angle at which a reflected ray A prism that deviates a beam of of light leaves a surface as light by REFRACTION. The measured from the NORMAL. angular deviation is a function Note: Angle 0 is angle of reflection. of the wavelength of light; therefore, if the beam is composed of white light, the PRISM will spread the beam into 1 '101 a spectrum of colors. L Defined as: D = 1og10( 1 ) Where R is the REFLECTANCE of the sample being measured. REFRACTION [12] The bending of a light ray or the change in its direction in passing from one transparent medium into another which has a different REFRACTIVE INDEX, e.g. air into glass. Note: Refraction occurs because the velocity of light varies The total REFLECTANCE of a layer according to the density of the of material of such a thickness media. that there is no change of reflectance with further increase REFRACTION ANGLE [4] in thickness. The angle between the refracted Note: See Figure 4 in the ray and the normal when a ray of appendix. light passes through a transparent substance. The REFLECTIVITY, SPECTRAL [5] refracted ray is bent at an angle from the line of the Approved For Release 20013@NF4DEt T 78B04560A007300010028-8 Approved For Release 2001.04 r l b REFRACTION ANGLE [41 (Continued) incident ray. Note: A is the refracted ray and B is the incident ray. Angle 8 is the Refraction Angle. B .1 B (1) The ratio of the velocity of light in a vacuum to the velocity of light of a particular wavelength in any substance is called the refractive index of the substance for light of that particular wavelength. (2) A measure of the power of a substance to refract (to bend a ray of light or change its direction) light. It is the ratio: . 78BO456OA007300010R??c'R-01 /72 Note: The greater the directional change the higher the Refractive Index, e.g. for air the index is 1.00029 and for glass, from 1.5 to 1.8. A device, usually of prismatic glass, which redirects light in desired directions by REFRACTION. REGISTER [5] To cause to correspond exactly; to adjust two or more images to correspond with each other. Such correspondence may be required either in printing or in projection. Regular transmission is that in which the transmitted light is not diffused. U.S. name for the METHUIN COLOR ATLAS. RELATIVE APERTURE [4] For a photographic lens, the ratio of the EQUIVALENT FOCAL LENGTH to the diameter of the ENTRANCE PUPIL. Expressed as f/4.5 or f:4.5; also called f-NUMBER. RELATIVE TILT [12] when ray is incident from the air side of a glass air boundary. The tilt of a photograph with. Approved For Release 20c GQI*iAD WTlh b78BO456OA007300010028-8 Approved For Release 20t3r(qftitAl1WQP78BO456OA007300019p?@ -01/72 RELATIVE TILT [12] (Continued) reference to an arbitrary plane, not necessarily a horizontal plane, such as that of the preceding or subsequent photograph in a strip. .RESOLUTION [4] (1) The minimum distance between two adjacent features, or the minimum size of a feature, which can be detected by a photographic system. For photography, this distance is usually expressed in LINE PAIRS per millimeter recorded on a particular film, under specified conditions. If expressed in size of objects or distances on the ground, the distance is termed Ground Resolution. (2) A measure of RESOLVING POWER Note: Color imagery may appear to have better resolution that what it, in fact, has due to the visibility of small color differences. (1) Expression of the fineness of detail that can be recorded by a lens/emulsion or collection system. Usually it is stated as the maximum number of lines per millimeter that can be resolved (i.e., seen as separate lines) in the image. The resolving power of a lens, film, or their combination varies with the contrast of the TEST CHART and normally varies also with the orientation and position of the chart within the field of view. (2) The minimum size of an image that can be resolved by the eye. It's roughly 25 to 50 seconds of arc. RESOLVING POWER, CHROMATIC [15] Some optical components such as prisms and gratings are used, not to resolve two or more object points but rather to separate two wavelengths of nearly equal value. The ability of an optical instrument to separate two wavelengths is called Chromatic Resolving Power and is specified as the ratio of the shorter wavelength divided by the difference between the wavelengths. A network of minute depressions or corrugations in-a negative, produced -- either accidentally or intentionally - by any treatment resulting in rapid expansion and shrinkage of the swollen gelatin. Reticulation may be produced by solutions which are too warm or too alkaline or by forced drying in an air current which is too hot. Note: The gelatin appears similar to cracked, dried mud. Approved For Release 20 IFiQ J*b78BO456OA007300010028-8 Approved For Release 200e3dNf D Re78BO456OA00730001 QWk$R-01 /72 The innermost layer of the three major layers of the eyeball, upon which the visual image is focused and serves as receptor organ for vision. In the human Retina 10 layers are distinguished, and the RODS and CONES are within the second layer from the exterior. Note: See Figure 1 in the Appendix. RETINAL FIELD [5] The extended mosaic of the ROD and CONE receptor elements of the retina which.forms something of an anatomical correlate of the visual field. RETINAL ILLUMINANCE [5] The illuminance on the retina, the usual units being the TROLAND and the LUX. as leaving their picture plane or physical plane and withdrawing further from the observer. Note: This illusion may cause exaggerated depths when viewing Retreating Colors through a stereoscope. REVERSAL FILMS, COLOR (1) Color of the processed film is same as the original scene or is POSITIVE. (2) Color films in which the residual silver halide is used to produce the positive dye image. Method of developing film first as a negative silver image, and then reversing the color values to form a positive. RETINAL IMAGE [5] RIDGWAY COLOR SYSTEM (1) The pattern of RADIANT ENERGY on the retina corresponding to external objects. (2) The image lying on the retina that is being viewed. An early system of 1115 pigment colors chosen to represent by relatively equal steps a wide range of variation in HUE, SATURATION, and LIGHTNESS. RMS (ROOT MEAN SQUARE) GRANULARITY RETINAL RIVALRY See BINOCULAR RIVALRY RETREATING COLORS These are generally blues and greens which tend to be perceived Approximately the standard deviation in DENSITY produced by the granular structure of an emulsion when uniformly exposed and developed as measured by a DENSITOMETER. Approved For Release 200'4 QEN.ItM78B04560A007300010028-8 Approved For Release 2O1 Q Q Ofb 78BO456OA00730001 m* -01/72 A rod-shaped structure found in the RETINA of the eye which constitutes a specific receptor for SCOTOPIC VISION. Note: The rods in the human eye are 0.04 to 0.06 mm long and about 0.002 mm in diameter. Distinguish from retinal CONES, another visual receptor; the Rods contain the chemical Visual Purple and are believed to operate for achromatic (gray) visual qualities at low light levels, while the cones for chromatic and achromatic at higher light levels; the rods and cones form the second layer of the retina from the outside lying just within the layer of pigmented cells; it is estimated that there are 130,000 rods in the human retina; at the FOVEA CENTRALIS there are no rods, farther out they are more numerous than the cones. Sight or vision in which only RODS function; the CONES of the retina do not participate. Also called TWILIGHT VISION, SCOTOPIC VISION. ROLL [41 (1) Air navigation. A rotation of an aircraft about its longitudinal axis so as to cause a wing-up or wing-down attitude. (2) Photogrammetry. A rotation of a camera or a photograph- coordinate system about either the photograph x axis or the exterior X axis. In some photogrammetric instruments and in analytical applications, the symbol omega (w) may be used. Approved For Release 20 IiDkJ*b78BO456OA007300010028-8 Approved For Release 200t'j DFlfllRt78B04560A00730001 Opgge$'R-01 /72 SAFELIGHT [4] A lamp for use in the darkroom which supplies light of a color which will not affect the photographic material within a reasonable time. Different photographic materials require different safelight filters. Note: Rarely recommended for fast color or panchromatic films. SATURATION analogous to SATURATION . SCALE [4] (1) The full range of tones (grays or colors) which a photographic paper is capable of reproducing is called the "scale" of the paper. (2) The ratio of a distance on a photograph or map to its corresponding distance on the ground. The scale of a photograph varies from point to (1) The degree to which any point because of displacements CHROMATIC COLOR (possessing a caused by tilt and relief, but it HUE) differs from an ACHROMATIC is usually taken as f/H where COLOR (gray) of the same lightness. f is the principal distance of (2) The amount of "color" in a color sample. The more "red" in a red color the higher its saturation. (3) The state of being saturated. A "saturated" red is a very vivid red. SATURATION SCALE [5] the camera and H is the height of the camera above mean ground elevation. Scale may be expressed as a ratio, 1:24,000; a representative fraction, 1/24,000; or an equivalence, 1 in. = 2,000 ft. The phenomenon of light diffusing or dividing in part into a variety A graduated series of colors which,! of different directions in passing under appropriately controlled through a medium. conditions of observation, are perceived to vary by uniform See RAYLEIGH SCATTERING; MIE steps in SATURATION alone. SCATTERING See PURITY DIFFERENCES The outer protective layer of the eyeball. SATTIGUNG [5] Note: See Figure 1 in the In the DIN COLOR SYSTEM; Appendix. 123 Approved For Release 200CONf4 DENTlIM78B04560A007300010028-8 Approved For Release 20e (V~ibE~tll ~P78BO456OA00730001pP2@fa-01/72 SCOTOPIC ADAPTATION See ADAPTATION, DARK SCOTOPIC VISION [5] Vision experienced by the normal eye when adapted to very low levels of illumination. The maximum of the relative spectral visual sensitivity is shifted to 510 nm and the spectrum is seen uncolored. The ROD receptors in the retina are considered to be the active elements under these conditions. standard calibrated by comparison with a PRIMARY STANDARD. The use of the term may also be extended to include standards which have not been directly measured against the primary standards but derive their assigned values indirectly from the primary source. SELECTED ORDINATE METHOD OF COLORIMETRIC CALCULATION [5] A method of INDIRECT COLORIMETRY in which the usual numerous multiplications are avoided by summation of the SPECTRAL DISTRIBUTION data at specially selected, nonuniformly spaced wavelengths. A chemical surface layer which SELECTIVE ABSORBER forms on developers, particularly pyro. Should be removed to A medium which does not absorb prevent marking of negatives. A line or axis formed by the central ray of an oblique bundle of rays passing through a lens. SECONDARY LIGHT SOURCE [5] A body or object transmitting or reflecting light falling on it from any other PRIMARY or SECONDARY LIGHT SOURCE. Note: The surface of a light- table is a Secondary Light Source. ,SECONDARY STANDARD [5] A secondary standard is a wavelengths of light equally. See ABSORPTION, SELECTIVE SELECTIVE RADIATOR [5] RADIATOR having SPECTRAL EMISSIVITY that is different for different wavelengths of the spectrum. Note: A colored light is a Selective Radiator. SELECTIVE SCATTERING [5] Scattering of RADIANT ENERGY so that the ratio of scattered flux to incident flux varies with wavelength. Approved For Release 20WiD78BO456OA007300010028-8 Approved For Release 200~bfi'MD f 78BO456OA007300010 3CR-01/72 SELECTIVE SCATTERING [5] (Continued) the response of a light sensitive material to a range of See Also: RAYLEIGH SCATTERING, exposures. There are two types of sensitometers: one which subjects the sample of material SEMICHROME to a series of lengthening exposures under a light of See OSTWALD SEMICHROME constant intensity, and the other which exposes adjacent SENSATION, COLOR [5] strips of the material for the same length of time to a Primitive awareness or uninter- range of light intensities. preted conscious response to stimulation of a visual receptor. SENSITOMETRIC CURVE Note: It is very difficult and generally unnecessary to distinguish Color Sensation from COLOR PERCEPTION (which is a better term for the awareness of color in the visual field). SENSITIZED MATERIAL [8] A strip of film exposed (generally through a STEPWEDGE) and processed under controlled conditions. Used for quality control and studying film and processing characteristics. films, and papers, etc. - that SENSITOMETRY [8] have been rendered light sensitive General term for all types of photographic material - plates, either by coating with an emulsion containing light sensitive silver salts or by impregnation with a chemical sensitizer. The science of measuring the sensitivity of photographic characteristics, e.g., SPEED, CONTRAST, EXPOSURE LATITUDE, and FOG, D-MAX, D-MIN, time/rate (time/gamma) of photographic materials. A chemical compound added to the Note: Sensitometry seeks to emulsion layer to provide establish accurately the sensitivity to a portion of the relationship between exposure SPECTRUM. and density for any given photographic material. The chief aim of sensitometry is to derive accurate numerical values An instrument used in recording for the exposure-density relationship of a material to SENSITOMETER [8] Approved For Release 200 DEIDiTAIM78BO456OA007300010028-8 Approved For Release 20Q3~/ ,~/o1f1b 78B04560A00730001@ -01/72 SENSITOMETRY [8] (Continued) eliminate guesswork and to state the results in units which can be universally applied and compared. SHADE [51 A term descriptive of a lightness difference between colors, the other attributes of color being essentially constant. A lighter shade of a color is one that has higher lightness but approximately the same hue and saturation, and a darker shade is one that has a lower lightness. A solution to stop the action of the DEVELOPER or color developer and to harden the gelatin. SHOULDER (of the CHARACTERISTIC CURVE) The high density area of the CHARACTERISTIC CURVE just above its The unrealistic perception of a color due to the influence of a nearby or surrounding color, i.e., the juxtaposed colors (CHROMATIC or ACHROMATIC) are different than when perceived alone. How colors affect one another is very complex but, in general,: a. A chromatic color tends to tinge the color near it with its COMPLEMENTARY COLOR. b. The eye accentuates the difference between colors. c. If two areas are the same color, the effect of their juxtaposition is a weakening of the intensity of their commonality. SKY, OVERCAST The sky when covered by haze or clouds so that the position of the sun is obscured and the illumination on the ground is even. STRAIGHT-LINE SECTION. SKYLIGHT A silver compound sensitive to light and used in film EMULSIONS to form a LATENT IMAGE which can be reduced to visible silver by DEVELOPMENT or removed and replaced with colored dyes. The light received from the sky as opposed to sunlight. Note: See Figure 3 in the Appendix. Note that Skylight is predominantly blue. SLOAN COLOR-THRESHOLD TEST [6] A diagnostic test of color vision which uses recognition of colored lights to measure degrees of red-green deficiencies Approved For Release 200( 1RI MN- 78B04560A007300010028-8 Approved For Release 200 14', b .fRl 78BO456OA0073000109?gc'R-01 /72 SLOAN COLOR-THRESHOLD TEST [6] without distinguishing type. Essentially a colored light is presented below threshold, then raised in intensity until the examinee can recognize the may confuse amber with red, green with white, and may be unable to see red at low intensities. SLUDGE[4] A muddy precipitate which forms in the bottom of processing tanks or bottles after use. Note: See Figure below. N ~ I &/////J/ i N2 SNOW-BLINDNESS [5] A temporary abnormality of color vision in which all objects are tinged with red. Caused by long-continued exposure to very bright light. SMALL AREA TRITANOPIA [6] See SUN ANGLE Isolated objects of very small angular size (about 15 minutes or SOLARIZATION [4] less) produce either a red or green hue or some shade of gray (from white to black) when viewed directly. Green-yellow or reddish-blue distinctions may not be perceived. A law which describes the behavior of a light ray as it passes from one media to another. It is: N1 sin 61 = N2 sin 62 - N1 = Index of refraction of incident medium 6 = Incident angle N2 = Index of refraction of refracting medium 62 = Refraction angle A reversal of the density gradation sequence in the image after intense or long-continued exposure. A still greater exposure appears to restore the original sequence of gradation. Note: The Figure below shows a CHARACTERISTIC CURVE. As exposure is increased, the density on the film eventually will decrease (dotted line) ; but as exposure is further increased, density will begin to increase again. N C a> 0 Exposure color. Color-deficient observers Approved For Release 200GjDNf4DEMTF k78BO456OA007300010028-8 Approved For Release 20Q ,(ff itt+t1WIC78BO456OA007300019p?@A-01/72 SOLID ANGLE green, yellow, orange, and red. The angle measured by the ratio SPECTRAL COMPOSITION of the surface of the portion of a sphere enclosed by the conical Distribution of any radiant surface forming the angle, to the quantity as a function of square of the radius of the wavelength. sphere. Note: In the figure below, 0 is the Solid Angle. , sphere SOURCE (LIGHT SOURCE) An object emitting radiant power. Note: In CIE terminology, a SOURCE is distinguished from an ILLUMINANT. See Also: ILLUMINANT SPECTRAL ABSORBANCE See ABSORBANCE, SPECTRAL SPECTRAL BAND A group of spectrum wavelengths which can vary from a small portion to almost the entire SPECTRUM. SPECTRAL COLORS [4] See Also: SPECTRAL DISTRIBUTION SPECTRAL CROSSTALK See INTER IMAGE EFFECTS SPECTRAL DISTRIBUTION The amounts of a radiant quantity for the various wavelengths of the SPECTRUM. Note: In the Figure below is shown the Spectral Distribution of a green leaf. Note that the radiant quantity (Reflectance) of each wavelength is shown. 400 500 600 Wavelength nm SPECTRAL EMITTANCE [20] An emiLttance based on the radiant energy per unit wavelength The continuous band of colors in interval. the VISIBLE SPECTRUM which are divided into seven basic spectral SPECTRAL ENERGY DISTRIBUTION colors: violet, indigo, blue, The relative energy (amount of Approved For Release 20CMIO 78BO456OA007300010028-8 Approved For Release 2003/e ft r1 ft g[8B0456OA0073000100R$1/R-01 /72 SPECTRAL ENERGY DISTRIBUTION (Continued) light) emitted from a source at each wavelength. Note: The plotting of the distribution (Relative Energy vs. Wavelength) for a source is called the Spectral Energy Distribution Curve. Ratio of the RADIANT FLUX of a narrow wavelength range leaving one face of a body to that reaching the opposite face. Note: In Figure below it is the ratio of A to B. A SPECTRAL IRRADIANCE See IRRADIANCE, SPECTRAL SPECTRAL POWER DISTRIBUTION wavelength interval at the wavelength X. The RADIANT INTENSITY per unit wavelength interval. SPECTRAL REFLECTANCE [20] The ratio of reflected flux to the spectrally homogeneous incident flux. Note: The measurement of Spectral Reflectance for each wavelength is often used to.plot curves of Reflectance vs. Wavelength for a particular sample. In the Figure below is a Spectral Reflectance curve for a red sample. .5 X0 0I i' 1 I L-- 400 500 600 700 Wavelength nm The power (energy per unit of time) of a light source at each SPECTRAL REGION wavelength. A portion of the ELECTROMAGNETIC Note: The plotting of the SPECTRUM. For example, the distribution (power vs.wavelength) Visual Spectral Region is from for a source is called the Spectral approximately 400 to 700 Power Distribution Curve. nanometers. SPECTRAL RADIANT ENERGY [5] SPECTRAL RESPONSE The RADIANT ENERGY per unit The response of a light detector 129 Approved For Release 2003I60Nf:I@Ai8B04560A007300010028-8 Approved For Release 2Q0OR/Ib4E RD P78130456OA00730001~Q~qTp 01/72 SPECTRAL RESPONSE (Continued) at each wavelength. Note: The plotting of the transparent sample. In the Figure below is a Spectral Transmittance curve for a red filter. response (generally 0 to 100) vs. wavelength is called the Spectral Response Curve. 0 0100 v SPECTRAL REFLECTANCE of a layer of 50 material so thick that further U) increase in thickness, however ? 0 ~ i I I great, produces no change in ~ 400 500 600 700 the value of spectral reflectance. SPECTRAL SENSITIVITY [8] The response of a photographic emulsion (or any light-sensitive material) to each of the separate colors (or wavelengths) of the SPECTRUM. SPECTRAL TRANSMISSION (of a filter) [5] The extent to which a filter will transmit radiant energy of different wavelengths. Shown graphically as transmission, opacity, or density plotted against wavelength. Wavelength nm SPECTRAL VISUAL SENSITIVITY See Spectral luminosity. SPECTRAZONAL PHOTOGRAPHY The imaging of narrow (or wide) bands of wavelengths by using appropriate filters over PANCHROMATIC FILM. Note: The purpose is to amplify target /background difference by using a filter which allows only the maximum, reflected wavelengths of the target to be imaged. SPECTRAL TRANSMITTANCE [5] See Also: MULTI-SPECTRAL PHOTOGRAPHY Ratio of transmitted to incident RADIANT FLUX of narrow wavelength SPECTROGRAM [4] range. A photograph of a spectrum taken Note: The measurement of Spectral through a filter which permits Transmittance for each wavelength the study of the absorption and is often used to plot curves of transmission properties of that Transmittance vs. wavelength for a filter. A scale on the Approved For Release 2TEM E"fJIMP78B04560A007300010028-8 Approved For Release 200 p?f 1. j fr 78B04560A0073000104 /R-01/72 SPECTROGRAM [4] (Continued) spectrogram shows the relative amount of transmission of various colors (or wavelengths). SPECTROGRAM, WEDGE See WEDGE SPECTROGRAM SPECTROGRAPH [5] A SPECTROSCOPE in which the ocular lens is replaced by a photographic plate. SPECTROMETER [5] (1) A SPECTROSCOPE fitted with a divided circle for isolating .or identifying wavelengths or regions of the spectrum. (2) A SPECTROSCOPE fitted with a divided circle, used to measure index of refraction of prisms. The measurement (using a SPECTROPHOTOMETER) of the absolute or relative energy within narrow bands of wavelength frequencies in the SPECTRUM. Generally presented in graphs where the abscissa represents the wavelengths of the visible spectrum (-400 to "700 nanometers) and the ordinate represents the relative energy or absolute energy (units depending on type of measurement). SPECTRUM (VISIBLE SPECTRUM) The band of colors or visible wavelengths resulting from white light being passed through a PRISM or other refraction mode. The resulting wavelengths or spectrum ranges from about 400 to 700 nanometers and the colors are VIOLET, INDIGO, BLUE, BLUE- GREEN, GREEN, YELLOW-GREEN YELLOW, ORANGE, and RED. An instrument for making a SPECTRUM COLORS SPECTRUM visible, thereby permit- ting visual or photographic (making SPECTROGRAMS) examina- tions. Usually, consisting of a slit, a COLLIMATOR, a dispersing element (usually a PRISM), and a second lens. Each wavelength of the SPECTRUM is a Spectrum Color, but they are usually grouped and called: VIOLET, INDIGO, BLUE, BLUE- GREEN, GREEN, YELLOW-GREEN,- YELLOW, ORANGE, and RED. SPECTROPHOTOMETER [5] A combination MONOCHROMATOR and RADIANT ENERGY of light of one PHOTOMETER used to measure SPECTRAL frequency or one wavelength. EMITTANCE, SPECTRAL TRANSMITTANCE, or SPECTRAL REFLECTANCE. Approved For Release 20030W I FElb k8B04560A007300010028-8 Approved For Release 200 3ff15Vt.6ft ,pP78B04560A00730001 RIB- -01X72 SPECTRUM LINE [5] Any one of the narrow lines, each representing light of a definite wavelength, which are observed on SPECTROGRAMS. Certain groups of lines being characteristic of specific chemical elements. SPECTRUM LOCUS [5] Note: Such as the reflection from a mirror. SPHERICAL ABERRATION [4] An aberration resulting in light rays passing through various zones of a lens coming to focus at different places along the OPTICAL AXIS. The locus of points representing the colors of the visible SPECTRUM Note: In the Figure below is an on a CHROMATICITY DIAGRAM is the example, where rays of light passing at the edge of the lens Spectrum Locus. l Note: See Figure 2 in the Appendix. SPECULAR [4] In SENSITOMETRY applied to a measurement made by collimated or essentially parallel light rays; referring to reflection or transmission without scattering or diffusion. The DENSITY measured by a densitometer when the incident light on the sample is highly COLLIMATED and the collection angle is small. SPECULAR REFLECTION [12] The type of reflection characteristic of a highly polished plane surface from which all rays are reflected at an angle equal to the angle of INCIDENCE. ens are focused closer to the than rays passing near its center. SPHERICAL CANDLEPOWER [5] The average candlepower of a lamp in all directions in space. It is equal to the total LUMINOUS FLUX of the lamp in lumens divided by 4 7T. SPREADING EFFECTS (ASSIMILATION) The unrealistic perception of a color because the color of its surround spreads onto it. A red object may appear darker if surrounded by black than if surrounded by white. Approved For Release 20COURDE1 TF t78BO456OA007300010028-8 Approved For Release 200t/ D la fl AI78BO456OA007300010R2$'R-o 1 /72 SPREADING EFFECTS (ASSIMILATION) (Continued) See Also: SIMULTANEOUS COLOR CONTRAST STANDARD [12] An exact value (a physical entity or an abstract concept) established and defined by authority, custom, or common consent to serve as a reference, model, or rule in measuring quantities or qualities, establishing practices or procedures, or evaluating results. A fixed quantity of quality. STANDARD ILLUMINANT [5] An agreed upon light source (real or hypothetical) defined by its SPECTRAL POWER DISTRIBU- TION. The hypothetical observer possessing the characteristics of color vision as adopted by the CIE. These characteristics of color vision are defined by the CHROMATICITY CO-ORDINATES of the equal-energy spectrum with reference to a specified set of primary colors. Note: In the Figure below are shown the characteristics of the CIE 1931 2? Standard Observer. 4J 0.32 U 0.28 .'. w t41 0.24 a) U 0.20 . 0.16 O 4' 0.12 0.08 4J m 0.04 400 500 .600, Wavelength, nm 0.00 -0.04 -0.08 -0.12 STANDARD OBSERVER, SUPPLEMENTARY See SUPPLEMENTARY STANDARD OBSERVER An object emitting radiant power with an agreed upon spectral distribution. See Also: CIE SOURCES STEP WEDGE (OPTICAL WEDGE) [4] A strip of film or a glass plate whose transparency diminishes and density increases in graduated steps from one end to the other; often used to determine the density of a photograph or a COLOR SEPARATION NEGATIVE. Approved For Release 200cJ611RIDhN- 8BO456OA007300010028-8 Approved For Release 2O5 thrtMP78BO456OA0073000100$,%-A-01 /72 STEP WEDGE (OPTICAL WEDGE) [4] (Continued) See Also: NEUTRAL DENSITY WEDGE; OPTICAL WEDGE; WEDGE; STEP TABLET STEP TABLET (STEP TABLE) A STEP WEDGE made either photo- graphically (often called Silver Step Tablet) or by dispersing carbon particles in gelatin (Called Carbon Step Tablet). two photographs acquired at different angles. Note: The stereoscopic vision of color imagery may be met with problems not encountered with black and white. a. The colors on the image pairs may be slightly different, thus resulting in a fused image of a false color or BINOCULAR RIVALRY. b. See ADVANCING COLORS; RECEDING COLORS The measure of the SOLID ANGLE subtended at the center of a c. See CHROMASTEROPSIS sphere when an area on its surface is numerically equal to the STILB square of the radius. A unit of luminance equal to 1 Note: In the Figure below the candela per square centimeter. size of the SOLID ANGLE is 1 Steradian. S/r2 = I = one steradian Appendix. The light entering the PUPIL of the eye near its edge is less effective in producing brightness than the light entering the center of the pupil. Because of this, the effective area of the pupil is smaller than the actual area. See Also: EFFECTIVE APERTURE The particular use of binocular vision to view objects or areas STOP-BATH [11] to obtain the mental impression of a three-dimensional view. Usually An acid bath into which films two different perspectives of an or prints are placed after object or area are needed, e.g., development to check any further Approved For Release 200 31'4 DEN,TII4Ak78BO456OA007300010028-8 Approved For Release 200a~ DE ~1~78B04560A00730001QQ~ $R-01/72 STOP-BATH [11] (Continued) SUBSTRACTIVE COLOR PRIMARIES developing action and to prevent The three primaries are: stains. CYAN (BLUE + GREEN), See Also: HARDENING STOP-BATH MAGENTA (BLUE + RED), and YELLOW (GREEN + RED). STRAIGHT LINE (of the CHARACTERISTIC .CURVE) SUN ANGLE The linear portion of the CHARACTERISTIC CURVE. STRONG COLOR [5] A color of high SATURATION. SUBTRACTIVE COLOR PROCESS (SUBTRACTIVE SYNTHESIS) [11] A method of creating essentially all the colors by using cyan, magenta, and yellow filters to subtract from white light the undesired colors. The subtractive color primaries are complementary to the additive primaries (red, green, and blue) selected so that they absorb only one-third of the luminous energy of a white light source. Thus, white minus CYAN = red; white minus MAGENTA = green; and white minus YELLOW = blue. In this way, by a suitable mixture of the three subtractive primaries, most colors can be produced by the Angle formed by an imaginary line projected from the sun passing through the collection platform and a plane tangent to the earth and perpendicular to the normal of the platform. Note: In the Figure below 0 is the Sun Angle. subtractive method using only one SUNLIGHT white light source. The light emitted from the sun. Note: Color Positive films use the Subtractive Color Process by See Figure 3 in the Appendix. layering CYAN, MAGENTA, and YELLOW DYES. Approved For Release 200 'i4I DE TkL78BO456OA007300010028-8 Approved For Release 20VbfP78B04560A00730001 aaA-01/72 SUNSPOT GLARE [4] LUMINOSITY CURVE. See Figure below: A "hot spot", a bright area 2.5r on an image lacking in detail and color often present in high- ,... _ -- 2.0 if are not taken to avoid the phenomena by using Solar Altitude ;1.5 Nomographs and Sun-Spot Templates.) SUNRISE AND SUNSET [8] Light at sunrise and sunset is 0.5 richer in red and orange rays than in the middle of the day. Thus, imagery acquired at high altitude close to sunrise or sunset may have a reddish or pinkish overcast. A tissue body in the brain in which some OPTIC TRACT fibers terminate. Here connections are marls coitl-, rrainial norvoc TTT TV 500 600 WAVELENGTH>, n m SURFACE-COLOR [5] Color seen as belonging to a surface or simply the color of an illuminated surface. and Vl serving retiex eye movements. SUPPLEMENTARY STANDARD OBSERVER Nerve junctions. SYNCHRONOUS FILM SPEED [4] A second STANDARD OBSERVER defined Movement of the photographic in 1961 by the CIE to correspond film in a camera at the same to the average human perception of rate of speed and in the same large (10? on the retina or more) direction as the movement of colored areas, in contrast to the the image during exposure for small (2?) areas used to define the purpose of eliminating image the 1931 CIE Standard Observer. motion. Note: For the SUPPLEMENTARY STANDARD OBSERVER, the function y1-0 is not the PHOTOPIC Approved For Release 20c6@Nf4DEMT t78BO456OA007300010028-8 Approved For Release 2003t6I 16 A[8B04560A0073000100283&/R-o 1/72 Green and red-purple, the colors that are between the WARM and COOL colors. TEMPERATURE, ABSOLUTE See ABSOLUTE TEMPERATURE TEMPERATURE, COLOR See COLOR TEMPERATURE TEST CHART Any chart used to test an acquisition system, e.g., using a set of LINE PAIRS for testing resolution or colors for testing color fidelity and balance. TEST STRIP [4] A strip of sensitized paper used as a preliminary test for exposure time in contact printing or enlarging before exposing a full sheet. TETARTANOPIA [5] Form of DICHROMATISM in which blue and yellow colors are confused and perceived as neutral. The existence of this form is disputed. A visual quality of the surface of objects, generally ranging from smooth to rough and shiny to dull. These dimensions affect the perception of colors; two identical reds may appear different if one is on a smooth, shiny surface and the other on a rough, dull surface. Thus, color matching should be done with the colors having the same surface texture. Radiation by solids heated to INCANDESENCE. Same as BRUNSWIK RATIO except log luminances are used and thus: log S - log S' log L - log S' See Brunswik Ratio for explanation. Note: Thouless Ratio is preferred over Brunswik Ratio. THREE-COLOR MIXTURE [5] It is usually possible to match a color with a mixture of suitable amounts of light of three selected colors. Note: The colors used for the mixture are commonly termed PRIMARIES and are usually red, green, and blue. See Also: NEGATIVE COMPONENT IN COLOR MIXTURE Approved For Release 2003/6Q IDI~RA8BO456OA007300010028-8 Approved For Release 20MM+M[C781304560A00730001ff?@A-01/72 THREE-COLOR PROCESS [5] Any process, either ADDITIVE or SUBTRACTIVE, for producing color photographs by the use of three PRIMARY COLORS. A statistically determined point or region along some dimension where sensory judgments occur TINTOMETER See LOVIBOND COLOR SYSTEM TOE [4] The portion of the characteristic curve below the STRAIGHT-LINE SECTION of the curve that represents the area of minimum useful exposure. regarding the first-perceptibility TONE or smallest perceived differences of stimuli (e.g., colors). The overall perceptual effect of a color or a colored photograph. See Also: DIFFERENCE LIMEN THRESHOLD, COLOR See COLOR THRESHOLD TIME-GAMMA CURVE [4] A curve which indicates the change in GAMMA obtained by changes in time of DEVELOPMENT. TIME-TEMPERATURE CHART [4] A chart which indicates the development times necessary at various development temperatures to produce approximately the same degree of contrast. TINT (1) A very light, desaturated color. (2) To lightly color. TINTING [5] Coloring film by dyeing the gelatin of the emulsion. Note: For example, "The image has a yellowish tone, a dark tone, etc." TONING [5] Coloring a film by chemical action on the silver image. TOTAL COLOR BLINDNESS [5] See MONOCHROMATISM TRACK The actual path of a collection platform over the surface of the earth. TRANSFORMATION, COLOR COORDINATES See COLOR COORDINATE TRANSFORMATION TRANSFORMATION OF COLOR-MIXTURE DATA [51 COLOR-MIXTURE DATA for one set of PRIMARIES can be used to Approved For Release 20c@ 3DMTI p78BO456OA007300010028-8 Approved For Release 2001 DcIRfaff78BO456OA0073000100P8ES'R-01 /72 TRANSFORMATION OF COLOR-MIXTURE DATA [5] (Continued) compute the color-mixture data for any other set of primaries, for the same observer. Such computations are known as Transformations of Color-Mixture Data. TRANSLUCENT [4] A substance is translucent if it allows light to pass through it but interferes enough with the passage of light to diffuse it to a large degree. Ground and opal glass, and thin paper are Translucent. TRANSMISSION [4] The amount of radiant energy of different wavelengths which a filter, lens, or film will transmit. Also called SPECTRAL TRANSMISSION. TRANSMISSION EFFICIENCY A measure (0 to 100 percent) of the ability of a medium to transmit light. Low efficiency means that light is lost by absorption and reflection. High efficiency, e.g. 90-100 percent, means that most of the light is transmitted. The loss of light during transmission through a medium. The INTERNAL TRANSMITTANCE for a unit thickness of a transmitting material. See Also: TRANSMITTANCE, INTERNAL The ratio of the transmitted RADIANT or LUMINOUS FLUX to the INCIDENT FLUX. Note: Simply the ratio of the amount of light coming out of a medium to the amount entering it. TRANSMITTANCE, INTERNAL The ratio of light reaching the the second surface of a medium to the light that has just passed through the first surface. Note: in the Figure below, the ratio of A to B. TRANSMITTANCE, SPECTRAL See SPECTRAL TRANSMITTANCE TRANSMITTED FLUX RADIANT FLUX that has passed through a medium. Approved For Release 2003,F06NKI:141A- TIR-6%8BO456OA007300010028-8 Approved For Release 20Mrl tRftA?P78B04560A00730001f@ $fq_01/72 TRANSPARENT [4] A term describing any substance which allows passage of light without scattering; the opposite of opaque. (1) An image upon glass or film, intended to be viewed by transmitted light. (2) A measure of the sample's ability to transmit light without scattering or diffusion or degradation of its image forming properties. TRANSPARENCY RATIO [5] The transparency ratio is the ratio of the parallel trans- mittance to the total trans- mittance of the sample. One who possesses TRICHROMATIC VISION. TRICHROMATIC COEFFICIENTS See CHROMATICITY COORDINATES TRICHROMATIC COLORIMETER A COLORIMETER which uses mixtures of three colors (usually red, blue, and green) to match a given sample. TRICHROMATIC THEORY [5] A color theory based on the facts of trichromatic mixture, namely that all hues may be derived from the mixture of two or more of the three PRIMARIES (usually red, blue, and green). The three inks used in making a three-color print. They normally correspond in color with the SUBTRACTIVE PRIMARIES (CYAN, MAGENTA, and YELLOW) but are usually called blue, red, and yellow. TRICHROMATIC VISION Same as Trichromatism. THRICHROMATISM A form of color vision yielding colors which require, in general, mixtures of three PRIMARIES (such as red, green, and blue) for their duplication. Normal color vision (NORMAL TRICHROMAT) or ANOMALOUS TRICHROMATISM are considered this form of vision. A composite filter containing areas of three PRIMARY colors. Any film consisting of three sensitive layers in the EMULSION. A type of theory which assumes that color vision depends upon the operation of three kinds of Approved For Release 20c3 NF4DENTFkMt78BO456OA007300010028-8 Approved For Release 20011 ' DEN fl F78BO456OA00730001 OO2& IR-01 /72 TRIRECEPTOR THEORY (Continued) retinal receptors. Usually they are CONES, each of which responds to a different color, e.g. red, blue, and green. All colors are perceived because of the inter- action of the three receptors. See Also: YOUNG-HELMHOLTZ COLOR VISION THEORY TRITANOMALOUS VISION (TRITANOMALY; a TRITAN) A form of ANOMALOUS TRICHROMATISM color deficiency which requires more blue to match a blue-green than normal. Also called blue- weak vision. TRITANOPIA (a TRITANOPE) A type of DICHROMATIC VISION in A COLORMETER using three or four which reddish-blue and greenish- broad-band filters to provide yellow colors are confused with measurements corresponding roughly gray and each other. Generally, to the blue, green, and red blue is not perceived at all. regions of the spectrum and (for most instruments) are convertible Note: In the population it by simple calculation to approx- affects approximately .002 per- imate CIE TRISTIMULUS VALUES X, cent of males and .001 percent Y, and Z. of females [6]. (1) See COLOR-MIXTURE DATA. TRITANOPIA, SMALL AREA Y, and Z are known as the A unit of visual stimulation Tristimulus Values. Each is defined as the illuminance on the found by integrating the area under RETINA which results when a the curve resulting from the point surface luminance of 1 candela (2) In the CIE COLOR SYSTEM, X, by point multiplication of the results of the SPECTRAL POWER DISTRIBUTION curve of the illuminant, times the SPECTRAL TRANSMITTANCE or REFLECTANCE curve of the color, times the appropriate (x, y, or z) COLOR MATCHING FUNCTION of the STANDARD OBSERVER. per square meter is incident through an apparent pupil of 1 square millimeter area. Note: The name of this unit has been changed from photon to Troland to avoid the confusion caused by the subsequent physical use of photon as a name for the quantum of electromagnetic radiation. Approved For Release 2003i9m41 IN-R,6 78BO456OA007300010028-8 Approved For Release 20c edff f fD 78B04560A00730001 Q PR-01 /72 The spreading of edges on imagery caused by the diffusion of exposing light in the emulsion. The amount of diffusion depends on the density and size of the silver grains which reflect and retract the exposing light. TWO-COLOR PROCESS Any process, either ADDITIVE or SUBTRACTIVE, for producing color photographs using only two colors. Approved For Release 200M' DEb,14M.78BO456OA007300010028-8 Approved For Release 2003ftg1pI TR- 78B04560A007300010 {$/R-01/72 ULTRAVIOLET [5] Radiant energy of wavelengths shorter than extreme violet and lying beyond the ordinarily visible spectrum. Usually assigned to wavelengths below 400 or 390 nanometers and extending to below 200 nano- meters. ULTRAVIOLET ABSORBING FILTER [4] A haze cutting filter used mainly in photography with color films to avoid excessive bluishness and loss of contrast in the pictures; usual designations are U.V.; HAZE FILTER; Wratten 2A. UNDERDEVELOPMENT [4] approximate equally perceptible steps of chromaticity. A system in which pairs of colors which are perceived as being equally spaced are plotted as being equally spaced. Note: The primary aim of this system is to transform the CIE CHROMATICITY DIAGRAM so that intervals on it are perceptually equal. On such a diagram a locus of points equidistant from a center point would be percep- tually equidistant from the center point. UNIFORM DIFFUSER [5] Insufficient DEVELOPMENT, resulting; A surface having a total reflec- in lack of density and./or contrast tion factor independent of the (desaturated, washed-out colors); angle of illumination and having caused by insufficient time in the LUMINANCE independent of the solution, or weak developer. angle of view. UNDEREXPOSE [4] To allow insufficient light to Hues perceived as not having reach the film or printing paper been mixed with adjacent SPECTRAL for proper exposure. Underexposed COLORS. They are red, green, color films are dark, very dense, yellow, and blue. and lack detail. UNIFORM-CHROMATICITY-SCALE COLOR DIAGRAM A color diagram resulting from a COLOR COORDINATE TRANSFORMATION of standard COLOR-MIXTURE DATA in. which equal linear distances See Also: PSYCHOLOGICAL PRIMARIES UVEA The CHOROID, CILIARY BODY, and IRIS form the UVEA. Approved For Release 200"Nkt Xb~ 48BO456OA007300010028-8 Approved For Release 20GSfflfi VA)P78BO456OA00730001$#Z -01/72 VALUE [7] characteristics of the surround, nature of the illuminant, etc. In the MUNSELL COLOR SYSTEM it is the expression of the LUMINOUS VIGNETTING [4] REFLECTANCE (lightness) of an object color on a scale of 0 A gradual reduction in density (Black) to 10 (white) giving of parts (generally at the edges approximately uniform perceptual and corners) of a photographic steps under the usual conditions image caused by the stopping of of observation. some of the rays entering the Note: Munsell Value of an opaque surface may (approximately) be found by taking the cube root of the LUMINOUS REFLECTANCE according to the equation V = 25Y1/3-17 lens. Thus, a lens mounting may interfere with the extreme oblique rays. VILLALOBOS COLOUR ATLAS [6] where V is Value and Y is Luminous A book of 7,279 glossy color VALUE LEVEL [5] A horizontal cross section through the COLOR SOLID on which all colors are of the same VALUE or brightness. VALUE SCALE [5] A series of visually equidistant neutral grays lying between black and white. VIEWING CONDITIONS [5] a 4-mm hole in. each to facilitate comparisons. There are 38 basic colors and for each one there are 19 series of colors. Within a series each sample has approx- imately the same daylight LUMINOUS REFLECTANCE as the corresponding gray. There are 20 such grays from black to white. Each chip is identified by a HUE letter, a BRIGHTNESS VALUE, and a number indicating the degree or CHROMATICITY (uniform SATURATION steps for a given HUE or BRIGHTNESS VALUE). VIOLET [5] The hue attribute of visual sensation t i ll d b k y evo yp ca e y The environmental conditions under which a visual observation is made stimulation of the normal human including the size of the stimulus, eye with shortwave radiation around 433 nm and shorter. Approved For Release 20( GQ14FAQ Tlh 78BO456OA007300010028-8 Approved For Release 200 ,3dNI?D RE78BO456OA00730001 Q $R_01 /72 See VISION, FOVEAL: PARACENTRAL VISION VISION, FOVEAL [5] Visual sensation or perception caused by simulation of the FOVEA CENTRALIS, which is nearly 100% CONES and is thus where color perception and discrimination are optimal. VISION, INDIRECT See VISION, PERIPHERAL VISION, PERIPHERAL [5] response to light in lower organisms; the higher psychological implications of light, color, form, and their spatial and temporal relations, etc. The anatomical and physiological basis may be, to a considerable extent, hypothetical, as is the case with the current theories of color vision. Note: See Table 2 in the Appendix. The ability of the eye to discriminate between fine differences of visual detail. VISUAL ADAPTATION Visual sensation or perception due to stimulation of outlying portions of the retina or non- FOVEAL VISION. VISION, PERSISTENCE OF [5] Adjustive change in visual sensitivity caused by continued visual stimulation or lack of stimulation. Three recognized types are (1) SCOTOPIC or DARK ADAPTATION, (2) PHOTOPIC or LIGHT ADAPTATION, and (3) CHROMATIC or COLOR ADAPTATION. changes in visual sensory response VISUAL ANGLE [5] The tendency of visual excitation to outlast the stimulus or, more generally, the tendency of to lag behind changes in the stimulus. VISION, THEORY OF [5] A systematic attempt to account for the various phenomena of visual perception in relation to the known structures and functions of the visual organs. Included by extension are the study of photoreceptors; the action of nerve-endings; related nervous structures in general, the The angle subtended by any object of vision at the NODAL POINT of the eye. The magnitude of this angle determines the size of the corresponding retinal image, independent of the size or of the distance of the object alone. The nodal point is about 7 mm behind the corneal surface and about 17 mm in front of the retina. Approved For Release 20031"kIJ1-T6F78BO456OA007300010028-8 Approved For Release 20t pb.~C QP78BO456OA00730001RPi? -01/72 VISUAL ANGLE [5] (Continued) Note: The visual Angle 0 is See VISUAL DENSITY usually approximated by measuring d as in the Figure below. VISUAL SENSITIVITY [5] D The ratio of LUMINOUS FLUX to RADIANT ENERGY FLUX. Nodal point of eye See Also: LUMINOSITY; LUMINOSITY FACTOR; LUMINOUS EFFICIENCY For the visual angle in radian, use 07= 57.3d D VISUAL SPECTRUM See SPECTRUM VISUAL TRISTIMULUS COLORIMETER A COLORIMETER in which the visual comparison field can be d d d juste to pro uce a continuous A COLORIMETER in which the a comparison color is adjusted until .,range of colors by modification it visually matches the sample of three stimuli, usually red, arison color is blue, and green lights. color The com . p changed in steps or continuous, depending on the type of colorimeter. See Also: VISUAL TRISTIMULUS COLORIMETRY. VISUAL DENSITY (LUMINOUS DENSITY) The DENSITY of a medium as it appears visually to the STANDARD OBSERVER. VITREOUS HUMOR [6] A clear, viscous liquid (specific viscosity in the range of 1.8 to 2.0) which fills the rear chamber of the eye between the lens and the retina. Note: See Figure 1 in the Appendix. Note: To measure the visual Color perceived as belonging to density of a medium, a densitometer is used which duplicates the human a definite tridimensional space PHOTOPIC CURVE (y of the CIE 1931 or volume. STANDARD OBSERVER). Note: The volume mode of visual appearance has the attribute of transparency, e.g., colored gelatin or jelly. Approved For Release 206 F4PENAJ IP78BO456OA007300010028-8 Approved For Release 200 / ['rlDt4 Q~78B04560A007300010P?@c 'R-01/72 VON KRIES COEFFICIENT LAW (6] The color response functions (x, y, z, of the STANDARD OBSERVER) under one set of adaptation conditions may be considered proportional to the response functions x', y', and z' under another set of adaptation conditions. Approved For Release 200fiEIDENT 8BO456OA007300010028-8 Approved For Release 20?.3/, vbrCt- pP78B0456OA00730001 AP $?-01 /72 WARM COLOR [5] Any color which produces in the observer a psychological reaction or impression of apparent heat is called a warm color, usually red to orange. WATT [4] Unit of electrical power equal to rate of work done by one ampere under an electrical potential or pressure of one volt. The distance between corresponding points on two successive waves, applied particularly to electro- magnetic radiations. These radiations range in wavelength sizes of a mile to a fraction of a millionth-of-an-inch (X and gamma rays). Wavelengths which are visible are called LIGHT and are measured in terms of the following units (NANOMETERS is preferred): Micrometer (um) 1 pm = 10-3mm Nanometer (nm) 1 nm = 10-6 mm Angstrom (A) 1 A = 10-7mm Note: Each wavelength may be thought of as a particular color. WAVELENGTH DISTRIBUTION See SPECTRAL DISTRIBUTION WEAK [4] A term used to describe a print or negative lacking density and contrast. WEAK COLOR [5] A color of low saturation. WEBER~FECHNER LAW [10] The minimum difference in light intensity which can be discrim- inated DI bears a constancy ratio to the intensity level I or SI/I = k. Note: This law does not hold true and thus is considered an approximation in the middle ranges of intensity level. WEDGE (STEP WEDGE, NEUTRAL DENSITY WEDGE, OPTICAL WEDGE) [8] In photography, a strip of material - such as glass - covered with a layer which is clear at one end and becomes more and more opaque towards the other end (density range from 0 to 5 or 6). Note: The layer itself may be a dyed gelatin, a suspension of pigment (such as carbon black) in gelatin, or a developed silver halide emulsion. The increase in Approved For Release 20IE1 Mk78B04560A007300010028-8 Approved For Release 200 ~Ia 78B04560A00730001? -@/R-01/72 WEDGE (STEP WEDGE, NEUTRAL DENSITY WEDGE, OPTICAL WEDGE) [8] (Cont'd) density may be smooth and contin- uous or in regular sections. The latter type is known as a STEP WEDGE. WEDGE SPECTROGRAM [8] Note: For comparison, a BLACKBODY absorbs all visible wavelengths. In the OSTWALD COLOR SYSTEM it is the amount of white in any color. The record of the SPECTRAL SENSITIVITY of a sensitized material made by giving a series of differing exposures to a SPECTRUM projected on to it. In practice the exposure scale is produced by placing a neutral density wedge over the sensitized material in such a way that each step of the wedge lies across the whole projected spectrum. This ensures that the material is subjected to the full range of exposures over every color. A SPECTROPHOTOMETER which uses a WEDGE to determine density. (1) The ACHROMATIC COLOR produced by emitting, reflecting, or transmitting all wavelengths of the visible spectrum equally or nearly equally. (2) The ACHROMATIC COLOR of maximum lightness. WHITE BODY [5] A term applied to a SECONDARY SOURCE which is nonabsorbing at all visible wavelengths. A color memory test in which the examinee is required to look at a colored test pattern and then asked to choose from a set of 4 response patterns one or none producing the same colors as the test pattern. Approved For Release 200N I:DiN- 8B04560A007300010028-8 Approved For Release 20p $f~itt~t1F [1P78BO456OA007300019pg@,4-01/72 The CHROMATICITY COORDINATE in the CIE COLOR SYSTEM for the x-axis of the CHROMATICITY DIAGRAM. The COLOR MATCHING FUNCTION in the CIE COLOR SYSTEM. The CIE TRISTIMULUS VALUE resulting from using X. The ordinate (x-axis) of the CHROMATICITY DIAGRAM. The numerical value for the x CHROMATICITY COORDINATE. Approved For Release 200WNf4DENTFiAk78BO456OA007300010028-8 Approved For Release 2003M,lf f yfXf78BO456OA0073000100 8f?/R-01/72 The CHROMATICITY COORDINATE in the (1) The hue attribute of visual CIE System for the y-axis of the sensations typically evoked by CHROMATICITY DIAGRAM. stimulation of the normal human eye with radiation of wavelengths approximately 577 nanometers. The COLOR MATCHING FUNCTION in the (2) Any color manifesting a hue CIE COLOR SYSTEM; the PHOTOPIC predominantly similar to that of LUMINOSITY FUNCTION if the 1931 the typical yellow (wavelengths CIE STANDARD OBSERVER is specified. 568 to 583). (3) The COMPLEMENT of BLUE. The CIE TRISTIMULUS VALUE resulting (4) The color resulting from the from using y. mixtures of red and green lights. See Also: MINUS-BLUE The abscissa (y-axis) of the YELLOW DYE CHROMATICITY DIAGRAM. y-VALUE The dye formed in the blue sensi- tive layer of an emulsion. The numerical value for the y CHROMATICITY COORDINATE. YAW [4] (1) AIR NAVIGATION: The rotation of an aircraft about its vertical axis so as to cause the aircraft's longitudinal axis to deviate from the flight line. Sometimes called CRAB. Note: In positive transparencies it is formed where blue wave- lengths were not imaged; thus stopping the transmission of blue except where it was imaged. In negatives it is formed where blue wavelengths were imaged, thus allowing its complement (YELLOW) to be transmitted. See Also: CYAN DYE; MAGENTA DYE (2) PHOTOGRAMMETRY: The rotation YELLOW-GREEN of a camera or a photograph coordinate system about either the (1) The hue attribute of visual photograph z axis or the exterior sensations typically evoked by Z axis. In some photogrammetric stimulation of the normal retina instruments and in analytical with radiation of wavelengths applications, the symbol kappa (K) approximately 565 nm. may be used. Approved For Release 2003 1 Q5W&AfBB04560A007300010028-8 Approved For Release 20Q Q5 ib WtIWIC78BO456OA00730001998r~_01/72 YELLOW-GREEN (Continued) (2) The complement of Bluish- Purple. YELLOW-SIGHTED [5] Characterizing a heightened color sensitivity for yellow. or a tendency to see all objects tinged with yellow. Note: The phenomenon occurs (1) in individuals who possess a peculiar pigmentation of certain tissues of the eye, (2) in normal individuals following blue-adaptation, or (3) following the use of certain drugs. A theory which seeks to explain the phenomena of color vision on the assumption of three independent component mechanisms (or processes) in the retina or its attached nervous apparatus; these mechanisms, .when separately aroused (chiefly by radiant energy of corresponding regions in the spectrum) giving rise to the colors, red, green, and blue, respectively; all other colors including yellow, purple, and white or gray being due to various combinations of the three component activities. Note: See Table 2 in the Appendix. Approved For Release 2O TlH)E P78BO456OA007300010028-8 Approved For Release 200t1WMIAf[AFL78B04560A007300010OR-o1/72 The rarely used CHROMATICITY COORDINATE for the z-axis of the CHROMATICITY DIAGRAM. The COLOR MATCHING FUNCTION in the CIE Color System. The CIE TRISTIMULUS VALUE resulting from using E. The numerical value for the z CHROMATICITY COORDINATE. Approved For Release 200 Nil:UAi 8BO456OA007300010028-8 Approved For Release 20tbvpibEf4tlWTP78BO456OA007300019 1o,-01/72 Approved For Release 20F1*. (p78B04560A007300010028-8 Approved For Release 200t/ 1olfiR fIA178BO456OA007300010@tM-&/R_O1/72 Fovea Vitreous Optic Disk (Blind Spot) Retina--i Optic nerve Approved For Release MEOW IEIN-TCI78BO456OA007300010028-8 Approved For Release 20ebfi5~i4.EWt11W~P78B04560A0073000109f?14-01/72 Spectrum Locus wavelength in nm Approved For Release 20W#f11}[ -hUp78B04560A007300010028-8 Approved For Release 200 MDT-M78BO456OA00730001OQ :- /R-01/72 Wavelength, nm FIGURE 3. Spectral energy distribution curves of skylight from different direc- tions and under different conditions at Cleveland, Ohio: (a) Zenith skylight, (b) North skylight, (c) Entire overcast sky, (d) Sun plus clear sky (daylight), and (e) Direct sunlight [3]. Approved For Release 2003f RIJ N-T 8BO456OA007300010028-8 Approved For Release 20ebVMbEfi f11A[1~P78B04560A00730001QD26/3-01/72 FIGURE 4. LIGHT UNITS [8]. A is LUMINOUS INTENSITY, or the amount of light emitted in all directions by a candle made to standard specifications. B is the light source of one CANDELA. C is LUMINOUS FLUX; the unit is the LUMEN. D is ILLUMINANCE or the luminous flux per unit area and is measured in LUX (lumens per square meter). E is REFLECTIVITY or the proportion of the incident light reflected by a surface. F is LUMINANCE or intensity of light reflected by a surface, measured in candela/square meter. Approved For Release 20 EM ikb78BO456OA007300010028-8 Approved For Release 200tle1FqDEIR:M1L78BO456OA0073000100284YR-01/72 Quantity Multiply number of By To obtain number of Luminous flux light-watts 680 lumens youngs 680 Illuminance lumens/square meter 1 lumens/square centi- 104 meter lux (lumen/meter2, phot 104 lm/m2) lumens/square foot 10.76 foot-candles 10.76 Luminance stilb 104 foot lambert 3.426 3 2 lambert 3.183E-10 candelas/meter (cd/m2 candle/ft2 10.76 meterlambert 1/II (apostilb) centimeterlambert 1/1IE+04 Approved For Release 200tNil:Q{N-T 8BO456OA007300010028-8 ) Approved For Release 20@1 bEf4tlAIP78B04560A0073000110 W/R-01/72 TABLE 2. SUMMARY OF THE BETTER KNOWN COLOR VISION THEORIES 16] Name A%natomieaI I'undanten- Relation to CIE Chief Limitation Location tat Colors Standard Observer Young, three compo- Cone pigments Red +3.1956.1 + 4.44781' - 0.6434Z Fails to explain dichromatic vision as in- nents Green -2.54551 + 7.049-2 1' + 0.4963Z tended. Violet + 5.000OZ Helmholtz, three com- Cone response Red +0.0701 + 0.945)' - 0.015Z Fails to explain color perceptions of pro- ponents Green -0.460X + 1.3591' + 0.1012 tauopes and deuteranopes. Violet + 1.000Z Dominator-modulator, Cone response Red + 1.0001' Fails to explain color perceptions of pro- late Konig Green -0.4601 + 1.3591' + 0.101Z tanopes and deuteranopes. Violet + 1.000Z Ladd-Franklin, three Cone response Red +3.76561 + 1.46351' - 0.22912 Implies that the blue function has a nega- component.s, early Green -1.39731 + 6.12891' + 0.2683Z tive luminosity for normals and deu- Konig Blue + 5.000OZ teranopes, positive for protanopes. Hering, opponent Optic nerve Red-green + 1.0(1131 - 1.000 Y Fails to give an account of protanopia and colors Yellow-blue + 0.4001' - 0.400Z tritanopia. White-black + 1.0001' Von Kries-Schro- ('one response ]led +3.7656.0 + 1.4635)' - 0.22912 Implies that the blue function has a nega- dinger. zone onstage Green -1.39731 + 6.1289Y + 0.26832 tive luminosity for normals and deu- Blue + 3.000()Z teranopes. positive for protanopes, fails to give an account of tritanopia. Optic nerve Green-red -3.537.V + 3.196) + 0.341Z Blue-yellow +1.341.0 - 5.884}' + 4.542Z White-black + 1.()001' Ilurvich-Jameson, Receptor response a + 6.53331' + 0.1333Z I Requires frequency-shift of photosensi- quantification of 6 -0.33331 + 7.00001' tive spectral distribution functions to Hering opponent y +0.33331 + 6.46671' - 0.1333Z account for protanopia and tritanopia. colors Neural response " lled-green k2[1.0000X - 1.0000}'J Yellow-blue k1[0.4000}' - 0.4000Z] White-black (k3 - k4)[20.0000)'l Adams, zone or stage Cone pigments Red +3.19561 + 2.4478)' - 0.6434Z Explanations of protanopia and tritan- Green -2.5455.1' + 7.04921' + 0.4963Z opia based on subsidiary assumptions. Violet + 5.000OZ Cone response Red +1.0001 Green + 1.0001' Blue + 1.000Z Optic nerve " Red-green +1.000.0 - 1.0001' Blue-yellow - 0.4001' + 0.4002 White-black + 1.0001' Muller, zone or stage Cone pigments Red +3.1956.0 + 2.44781' - 0.64342 Implausible explanation of protanopic Green -2.5455X + 7.04941' + 0.49632 luminosity by resort to luminosity of Violet + 5.000OZ the yR cone response and luminosity- inhibiting action of the bG cone re- Cone response " yR-bG +5.7411 - 4.601)' - 1.140Z sponse, both of which disappear with y}'-rB -0.9321 + 2.7501' - 1.8192 the yR-bG cone response to produce Luminosity + 1.0001' protanopia. Optic nerve Red-green +6.345.1' - 6.3251' Yellow-blue + 2.0041' - 2.004Z White-black + 1.000 Y Approved For Release 20M1 f } P78B04560A007300010028-8 Approved For Release 20031N f Mf 8BO456OA007300010 D/R-01/72 (1) Wyszecki, G. and Stiles, W. S., Color Science, 1st ed., John Wiley and Sons, New York, 1967. (2) Judd, D. B. and Wyszecki, G., Color in Business, Science and Industry, 2nd ed., John Wiley and Sons, New York, 1963. (3) Evans, R. M., An Introduction to Color, 1st ed., John Wiley and Sons, New York, 1948. (4) Manual of Color Aerial Photography, Editor John T. Smith, Jr., American Society of Photogrammetry, Arlington, Virginia, 1969. (5) Comparative List of Color Terms, a Report, Compiled by Newhall, S. M., and Brennan, J. G., Inter-Society Color Council, Washington, D. C., 1949. (6) Burnham, R. W., Hanes, R. M., and Bartleson, C. J., Color: A Guide to Basic Facts and Concepts, John Wiley and Sons, New York, 1963. (7) Wintringham, W. T., "Color Television and Colorimetry", Proceedings of the Institute of Radio Engineers, No. 39, pp?1135-1172. (8) The Focal Encyclopedia of Photography, Focal Press, London-New York, 1965. (9) Bennett, A. H., Glossary of Terms Frequently Used in Optics and Spectroscopy, American Institute of Physics, New York, 1962. (10) Evans, R. M., Hanson, W. T., and Brewer, W. L., Principles of Color Photography, John Wiley and Sons, New York, 1953. (11) Sowerby, L. M., Dictionary of Photography, 18th ed., Philisophical Library, New York, 1957. (12) Manual of Photogrammetry, 3rd ed., Thompson, M. M., Editor, American Society of Photogrammetry, Arlington, Virginia, 1966. (13) Optical Terms and Definitions, Military Standard, MIL-STD-1241A, March 31, 1967. (14) Glossary of Optical Terms, Bausch and Lomb (an unpublished pamphlet). Approved For Release 2005/6'S)I4J Pc . 78B0456OA007300010028-8 Approved For Release 2MME f T fAt P78B04560A0073000 Q:t$i$01/72 (15) Judd, D. B., "Basic Correlates of the Visual Stimulus", in Handbook of Experimental Psychology, Edited by S. S. Stevens, John Wiley and Sons, New York, 1951. (16) LeGrand, Y., Light Colour and Vision, 2nd ed., Chapman and Hall, Ltd., Ltd., London, 1968. (17) Billmeyer, F. W. and Saltzman, M., Principles of Color Technology, Interscience Pub.,. Div. of John Wiley and Sons, New York, 1966. (18) Committee on Colorimetry, Optical Society of America, The Science of Color, Thomas Y. Crowell Co., New York, 1953. Reported by the Optical Society of America, 1963. (19) Mees, C.E.K. and Jones, T. H., The Theory of the Photographic Process, 3rd ed., The MacMillan Company, New York, 1966. (20) American Society for Testing and Materials, 1970 Annual Book of ASTM Standards, Index and Glossary, Part 33, November, ASTM, Philadelphia, Pennsylvania, 1970. (21) American Society for Testing and Materials, 1970 Annual Book of ASTM Standards, General Testing Methods, Part 30, July, ASTM, Philadelphia, Pennsylvania, 1970. (22) American Society for Testing and Materials, "Nomenclature and Definitions Applicable to Radiometric and Photometric Characteristics of Matter", ASTM Special Publication No. 475, ASTM, Philadelphia, Pennsylvania, 1970. Approved For Release 20EiWFIDENIVP78BO456OA007300010028-8 Approved For Release 200C33 1I~-C~I;ARCP78BO456OA007300010028-8 Approved For Release 20q FIBENTWP78BO456OA007300010028-8