EVALUATION OF REAR PROJECTION VIEWERS

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B05171A000100050002-2
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 2
• Document Creation Date: December 28, 2016
• Document Release Date: February 5, 2004
• Sequence Number: 2
• Publication Date: December 16, 1965
• Content Type: MF

Approved fpr Relea 200ii0A -CIA-RDP78B0 i1 A000100050002-2
IPO/OSS/M-1165
16 December 1965
;vrx.,OFJINDUM FOR, The Record
IJTUL;CT: Evaluation of Rear projection Viewers
26
1. An evaluation by the Photographic Analysis Group has been completed
determing illuminance and resolution at the viewing screen for the
705-V,
rear projection viewers.
One each of the
25X1 and
25Xh and
instruments were available. Arbitrary selection of a
Viewer was made. No special techniques were applied to any of the instruments
the testint procedures carried out.
2.. Illuminance tests were made by using a
tested and it is considered that a fair evaluation was made for all, under
illuminance measurements were made by an iphotometer for both the
photometer with a
meter which sensed approximately a 2" diameter screen area. Angular
none were made on the
0
When high illuminance
readings co.,ld not be made due ,to limitations on the meter scale, a 1.0.,
neutral density filter was placed on the screen and the sensor illuminance
read through the filter. These readings were multiplied by 10 to determine,
r
the corrected readings. Angular illuminance readings were taken at the center
of the screen at angles of 00 and at 15?, 300, 4+5? to the left and right of
the projected screen axis. Readings below 100 foot-lamberts were not taken.
Declassification Reveiw by
NGA/DoD
W I.,
ExLUadad ?ra:;
CAN
oC ca~slfi Approved For Release 2004/03/26 : CIA-RDP78BO5171A000100050002-2
25X1
25X1
25X1
25X1
 SUBJECT :
necessarily) the lower the amount of color fringing. One of the best lenses
3. Resolution readings were made using three-bar targets recorded
on 70mm film. All target resolutions on this film were capable of transmitting
a 228 l/mm target. This was verified by checking each target through use of
2 dX1 Iigh Power Stereoviewer. Color fringing made resolution determination
difficult. Generally, the higher the recorded resolution (not magnification
2$X1
was, surprisingly, the
rN}' :
Approved Felease 2004/03/26 CIA-RDP78B051gi1A000100050002-2
Evaluation of Rear Projection Viewers
115X lens.-
4+. These test were made by personnel having no prior experience in
testing equipment; however, sufficient instruction and spot checks were
made to/insure the validity of these recordings. A listing of the results
of all tests are attached to this memorandum. These recordings are not to
be construed as the maximum capability of the instruments tested when
optimum conditions are present but rather the capability of the instruments
under normal working conditions with maintenance provided when required.
25X
25X'l
Chief, Logistics Support Section, PAG
Attachment;
Test Results
CONF1C E + IAL
Approved For Release 2004/03/26 : CIA-RDP78BO5171A000100050002-2