DEAR ED:

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04747A002400010004-1
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 12
• Document Creation Date: December 28, 2016
• Document Release Date: April 17, 2001
• Sequence Number: 4
• Publication Date: December 22, 1964
• Content Type: LETTER

Arlington, Virginia 22209
Attention:
Dear Ed :
Attached please find two (2) copies of our Preliminary
Instructions for Use, relating to the Anamor?phic Eyepieces.
Final instructions are being prepared and will be keyed to
a photograph or diagram. These will be forwarded in the
near future.
Declass Review by NIMA / DoD
Fxcl Grow
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S A$proved or Release 200 /07~t - - 0,647Xb024~OOO~f000T4-11 N 6 S
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VARIABLE ANAMORPHIC EYEPIECES
Preparing the Microscope to Accept the Eyepieces
One of the eyepiece tubes on the Bausch & Lomb Microscope
is topped with a d 'ustable collar. This m ;Tt4 V4TL
removed and replace w z ze ixed collar Wh~T }TI -L
locked in place with a set sc justable collar is
normally found on the left hand eyepiece tube.
To adjust the dollar to the proper heightSTATINTL
focus the microscope on an o ect while looking through the
right eyepiece. (Anormal lOx eyepiece). Then, using the same
eye, examine the object through the left eyepiece. I it is
out of focus, adjust the tube by rotating the collar until the
object is in focus. Lock the collar in place by tightening the
set screw with a small driver. i
One of the Variable Anamorphic Eyepieces does not have a
tube collar. Screw the adjustable tube collar which was removed
from your microscope onto this eyepiece.
Explanation of the External Parts of the Variable Anamorphic Eyepiece
Externally the Variable Anamorphic Eyepiece appears to con-
sist of a series of metal rings of various shapes and sizes.
These rings serve either to support or control the internal work-
ing parts of the instrument. The operation of the individual
eyepiece will be described in terms of them beginning at the
eyepiece tube collar which is screwed onto the eyepiece tube at
the top of the eyepiece.
Located approximately an inch below the eyepiece tube collar
are two graduated rings. These indicate the amount of anamorphic
magnification being introduced by the eyepiece. The upper one
has a single index mark-. The lower one is graduated from lx to
2.7x in steps of lx magnification.- The upper ring is fixed with
respect to the eyepiece tube, the lower ring revolves as the
magnification of the eyepiece is changed.
Below the graduated magnification index ring is the magnifi-
cation control ring. This is a wide knurled ring which drives
the zoom system and controls the anamorphic magnification of the
eyepiece. Rotating it clockwise with respect to the eyepiece tube
increases the anamorphic magnification.
Following the magnification control ring is a black ring which
is knurled on two sides, and open on two sides to expose the
cromeplated ring beneath it. This is the asimuth control ring,
and it is used to orient the direction of the anamorphic magnifi-
cation. There is a, single white line on one side of this ring
which indicates the power plane of the eyepiece. The orientation
of this plane may be read from the 3600 graduated circle found
below the index mark. This circle is graduated every 2.5 degrees.
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Between the azimuth control ring and the graduated circle
is the azimuth lock ring. It is the cromeplated ring which is
partially covered by the azimuth control ring. Rotating this
ring clockwize locks the azimuth control ring with respect to
the graduated circle. It should be set just tight enough to
prevent the eyepiece from turning as the magnification is being
changed.
Beneath the graduated circle is a fixed knurled ring with
which one can grasp the eyepiece when loosening or tightening
the azimuth lock ring orp the tube clamp ring which is below it.
The tube clamp ring is rotated in a counter-clockwize direction
to lock the eyepiece to the microscope.
Placing the Eyepieces on the Microscope
Focus the microscope on an object and remove the normal
eyepieces. Insert the variable anamorphic eyepieces into the
microscope eyepiece tubes. Loosen the lock rings if necessary.
Orient the eyepieces so that the 180? graduations are exactly
opposite one another. Lock the tube lock rings only tight,
enough to hold the variable anamorphic eyepieces in place. Place
the eyepieces previously removed from the microscope into the
.eyepiece tubes of the variable anamorphic eyepieces. (The focus
of the microscope should not have been disturbed during this
process). Look into the microscope and screw the eyepiece tube
collars in or out until the object is in focus.
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VARIABLE ANAMORPHIC
EYEPIECES
FIRST MONTHLY PROGRESS REPORT
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SUMMARY
In the first month optical design has been completed.
A preliminary mechanical layout has also been completed.
This shows the overall length of the unit to be about 5.5
inches from Zoom 70 eyepiece shoulder to the shoulder of
the upper eyepiece mount.
Optics have been released for manufacture with a
promise date of completion in one month. Delay in comple-
tion of optical design slipped the original schedule by
three days. Every effort is being made to gain these three
days, but the original schedule was so rigid that this may
not be possible. Thus a real possibility of a few days
slippage in final delivery exists.
The unique nature of this eyepiece has presented some
difficulty in analysis by conventional lens design tech-
niques. Scheduling did not permit an exhaustive study of
this problem. Thus there is still some question as to
the meaning of the results of design analysis. Imagery
will be excellent on axis and out to about half full field.
Beyond that, it is very good by present interpretation of
results, but more study of this problem is required.
Progress This Month
Optical Design
Two design approaches, as proposed, were initiated.
One achieved the required anamorphism by use of tilting
prisms while the second used a cylindrical zoom lens arrange-
ment. Approximately two weeks of effort showed that it
would be impossilbe to reduce the length of the prism sys-
tem to six inches or less. Hence, this approach was
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abandoned and all efforts were concentrated on the cylinder
system.
Basically the arrangement consists of a modified eye-
piece to collimate the light from the image plane of the
Zoom 70, the variable power cylindrical lens system, and
an objective system to form a real image. In the no power
plane, the modified eyepiece and objective lens form a one
to one relay system. The final image is then viewed with
the conventional Zoom 70 eyepiece. Thus lOX or 20X power
is available depending on the upper eyepiece used. The
finally achieved zoom ratio is 2.8 to 1.
Originally it had been hoped that the cylindrical var-
iable power system would be of the optically compensated
type with single linear motions of the moving lenses. How-
ever, in the present arrangement, the image formed in the
no power plane is constant independent of the cylindrical
lens positions. Optically compensated zoom systems always
have some drift of focus which is usually not noticeable.
In the present case, a fixed referrant (the image in the
no power direction) exists and it was felt the normal
optically compensated variations of focus would be notice-
able. Hence, the system was changed to mechanically com-
pensated to permit maintenance of exact position of focus
throughout the zoom.
The interpretation of analysis results is a problem
with this system. The usual method of analysis is to trace
rays from a point in the object plane and find their inter-
section in the image plane. Ideally, they should all meet
in a single point. In practice they seldom do and much of
-2-
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the art of lens design resides in interpretation of just
how much deviation is acceptable. With cylinder lenses
present in the system, the results of analysis differ depend-
ing on whether the assumed ideal object point lies in a
plane containing the cylinder lens axes or in a plane per-
pendicular to the axes. To meet delivery commitments, it
was necessary to ignore this uncertainty, rapidly develop
an interpretation scheme, and do the best job possible
within this method of interpretation. As a result, there
is some uncertainty as to image quality at the edge of the
field. Present interpretation is that some astigmatism
will be present in the image of the object lying in the
plane containing the cylinder axes, and there will be neg-
ligible astigmatism in the image of the alternate object
described above. In any event, the axial image will be
excellent and imagery should remain very good throughout
at least half the field.
An optical schematic of the system as released for
manufacture is shown in Fig. 1.
Mechanical
In the third week of optical design, the then exist-
ing configuration was released for mechanical design with
the full realization that minor changes would be necessary
as optical design was completed. A preliminary layout was
completed that meets all requirements.
As noted in the original proposal, it is necessary to
bend the system through about a two-degree angle to main-
tain interpupillary distance. This means that it is
necessary to rotationally adjust the unit in the stereoscope
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at the time of insertion and then lock it. Rotation of
the anamorphic plane must then be accomplished at a bear-
ing above this lock. Finally, it was deemed desirable to
have the zoom control a rotational adjustment of a sleeve
fitting around the eyepiece. All of these objectives have
been met in the layout.
This layout is now being revised to conform to the
final optical design. After completion of this step,
necessary detailing will be done, and drawings released
for manufacture.
Present length is 5.5 inches from the existing Zoom
70 eyepiece shoulder to the shoulder on which the upper
eyepiece will rest.
Because of its preliminary nature, no sketch of the
existing layout has been included with this report.
Future Plans
Optical
The manufacture of the optical components will be
carefully monitored to assure completion within the re-
quired time. Engineering personnel familiar with the
job are being made immediately available to manufactur-
ing personnel to answer any questions that may arise.
The question of interpretation of analysis results
is being given continued consideration. When this has
been resolved, there will exist a clearer understanding
of the imagery at the edge of the field.
A very thorough and complete tolerance analysis of
the system is being made. The effects of variations of
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all parameters is being carefully investigated. This is
being done to reduce the amount of time required to "tune
up" the system at final assembly. ordinarily, it is cheaper
to do this more or less by a "cut and try" method at the
final assembly stage. In the present case, however, the
delays associated with such a procedure are intolerable,
and the more expensive method of machine analysis must be
adopted.
Mechanical
The preliminary layout is currently being updated to
conform to final optical design. This operation, plus
necessary detailing, should require only a few days. It
is expected that mechanical parts will be released for
manufacture within a week after the optical parts were re-
leased.
Conclusion
There has been approximately a three-day slippage in sch-
edule which may not be recoverable. There is every reason,
however, to be optimistic about the successful design of
a unit to meet the requirements for a variable anamorphic
eyepiece.
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F(C.:URE I
OPTICAL SCHEVAT,C 'OF VAR1A ,I A;\1AMORPHC EYEPIECE'
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