TEST PROCEDURE FOR (Sanitized) DIRECT IMAGE VIEWER

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04747A001500020043-7
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 15
• Document Creation Date: December 28, 2016
• Document Release Date: February 13, 2002
• Sequence Number: 43
• Content Type: REPORT

STATINTL
?
DECLASS REVIEW by NIMA/DOD
Approved For Release 2002/06/17 : CIA-RDP78B04747A001500020043-7
for
DIRECT IMAGE VIEWER
Project 7506
Approved For Release 2002/06/17 : CIA-RDP78B04747A001500020043-7
 Approved For Release 2002/06/17 : CIA-RDP78B04747A001500020043-7
0
STATINTL
STATINTL
?
1.1 The Direct Image Viewer employs a unique optical approach
involving diffraction gratings to provide an observer with an
enlarged aerial image which can be viewed simultaneously with both
eyes.
1.2 This document lists the tests and inspections to be
performed that, when satisfactorily completed, show that the
viewer meets the specifications listed.
2.0 APPLICABLE DOCUMENTS
2.1 II Specification for Direct Image Viewer, 25 August
1964.
2.2 Phase II Development of an Experimental Direct (Virtual)
Image Viewer, 28 February 1964. (SECRET)
2.3 II Drawing 7506L1 Layout Dual Magnification Direct
Image Viewer
2.4 Handbook for Direct Image Viewer
3.0 REQUIREMENTS
2.1 This viewer has been designed to meet the general
requirements set forth in Section 3.2 of the document listed in
Section 2.1. Consideration has also been given to the objectives
listed in the Secret document listed in 2.2.
This is a prototype experimental viewer and therefore only
the minimum specifications were imposed to allow for flexibility
in the design and manufacture.
Section 3.2 of the specifications is listed below for
convenience in verifying the test procedures.
Approved For Release 2002/06/17 : CIA-RDP78B04747A001500020043-7
 Approved For Release 2002/06/17 : CIA-RDP78B04747A001500020043-7
0
?
3.1.1 Magnification - dual individual magnifications
of 5X and 50X.
3.1.2 Observable Film Area - the observable film area
shall consist of a nominal two inch by two inch square area
in the film plane at 5X magnification, and two-tenths inch
square area in the film plane at 50X magnification.
3.1.3 Film Size - the viewer shall possess a
capability for viewing single frames of either 70mm or
4 x 5 inch film chips.
3.1.4 Exit Pupil Size - the nominal size of the
composite exit pupil shall be 3.5 inches square.
3.1.5 System Resolution - at'5X magnification, the
experimental direct image viewer shall be capable of
providing a system AWAR resolution of 25 1/mm over the used
field when referred to a high contrast target in the object
plane. At 50X magnification, the viewer shall be capable
of providing an on-axis resolution of 200 1/mm at the film
plane with a high contrast target while employing
commercially available lens. The resolution goal of the
system, when operating at 50X, shall be 200 1/mm as viewed
in the object plane for a low contrast (1.6:1) target.
3.1.6 Light Intensity - the illumination system shall
be variable and will present to the eye, with an open film
gate, at least that amount of light flux as presented to
the eye by a lambertian source with illuminance of 100 ft-
lamberts.
3.1.7 Illumination Spectrum - the illumination of
the viewer system shall be contained in a narrow portion
of the spectrum centered around 508.6 mp.
3.1.8 Film Positioning - the viewer shall incorporate
a provision for remote film positioning through X and Y
translations to permit full coverage viewing areas for
either 70mm or 5 inch film chips.
Approved For Release 2002/06/17 : CIA-RDP78B04747A001500020043-7
 Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
3.1.9 Focusing - a manual fine focus control shall
be provided for each viewer lens magnification.
3.1.10 Film Temperature - the temperature of the film
when mounted in the film plane of the viewer during opera-
tion shall not exceed ambient (75?F) by more than 20?F
at an average density (silver) of O.B.
3.1.11 Viewer Controls - the experimental direct image
viewer shall contain a set of viewer controls, front panel
mounted, consisting of the following:
0
3.1.11.1 Power - ON/OFF
3.1.11.2 Intensity of Illumination
3.1.11.3 Magnification Selector, 5X and 50X
3.1.11.4 Lens Focus, 5X and 50X
3.1.11.5 Film Translation
+ two inch X
+ two inch Y
STATINTL
3.1.12 Physical Size - (Reference II Dwg. No. 7506L1).
The viewer shall consist of the following general dimensions:
length - 66 inches, height - 26 inches, width - 29 inches.
? 3.2 Theory of Operation
In direct viewing optical instruments, such as a microscope,
the exit pupil is small, requiring that the operator place his
eye close to the eye piece for satisfactory viewing. The present
Experimental Direct Image Viewer, with its larger optical elements
and diffraction grating, enlarges the exit pupil in a manner
that the operator may view with both eyes the image and still
have adequate head movement. In the absence of employing
diffraction gratings in the present viewer, a single small exit
pupil would exist, which would restrict the operator to the use
of a single eye and no head movement when viewing at high
Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
 Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
magnifications. Through the insertion of the gratings in the
optical path, and the use of a narrow portion of the spectrum,
many exit pupils are created, which when arranged side by side
and placed both above and below one another, form a matrix of
exit pupils in space providing an effective viewing area of 3.5
square inches, where the operator may place his eyes for viewing.
This unique approach results from the use of a special field
lens, and specially designed and built set of diffraction
gratings. Near monochromatic light must be used with the viewer,
or the diffraction characteristics of the gratings will produce
multicolored exit pupil elements.
?
4.0 QUALITY ASSURANCE PROVISIONS
Acceptance test and inspection will be performed to show
compliance with the requirements stated in Section 3.0.
4.1 Inspection
4.1.1 Inspect the viewer for overall workmanship in
compliance with the statements made in Section 3.1 of the
? referenced specification. This statement is given below. The
viewer shall employ materials of highest commercial quality
consistent with its intended performance and specified operating
environments.
Record comments in Section 6.1.1 of Data Sheet.
4.1.2 Determine physical size of machine and record
in Section 6.1.2 of Data Sheet.
Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
 Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
4.2 Operational Test Procedure
Details on how to perform the various steps and tasks
required by this procedure are given in the viewer manual.
4.2.1 Prepare the viewer for operation. In performing
this task connect volt and amp meter to the input line so that
the power consumed may be measured and entered in Section 6.1.3.
4.2.2 Load the two film holders with 4 x 5 and
70 x 100 mm film chips.
4.2.3 Insert the 4 x 5 holder in the viewer.
4.2.4 Turn on the machine.
4.2.5 Vary the intensity over the full range.
4.2.6 Translate the film in X and Y over the entire
4.2.7 Check on the data sheet for compliance with
requirements No. 3.1.3, 3.1.8.
4.2.8 Operate the 5X manual fine focus knob and run
the image "through focus".
? 4.2.9 Change to 50X and operate the 50X manual fine
focus knob to run the image "through focus".
4.2.10 Check on the data sheet compliance with require-
ments No. 3.1.1, 3.1.9 and 3.1.11.
4.2.11 Return to 5X magnification and remove the film
chip.
4.2.12. Change the viewer to 50X.
4.2.13 Place a screen 13 inches in front of the
viewer; at the exit pupil plane. Measure on this screen the
size of the total exit pupil. Record this measurement on the
data sheet, Section 6.1.6 for compliance with requirement 3.1.4.
Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
 Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
0
4.2.14 Place a calibrated photometer probe in the
exit pupil plane and measure the illuminance falling on the
probe. The 3.5" x 3.5" exit pupil should contain 0.68 Lumens.
This is equivalent to 32 watts
cm
Record the measurement made in Section 6.1.7 on the data
sheet for compliance to requirement 3.1.6. As it can be shown
by calculation that a lambertian source with an illuminance of
100 ft/lamberts places 0.68 Lumens in the exit pupil plane area.
4.2.15 Return to 5X magnification position.
4.2.16 Insert the 70mm holder containing the resolu-
tion target.
4.2.17 Translate the film so that the target appears
in the center of the screen and adjust for best focus.
4.2.18 Read the resolution and record in Section 6.1.8
of the data sheet.
4.2.19 Move the target to all four corners of the
viewing area and read and record -the resolution on the data
sheet. Verify that all readings are above the requirement
stated in Section 3.1.5.
4.2.20 Center the resolution target and then translate
4.2.21 Focus the lens and read and record the
resolution on the data sheet in Section 6.1.9. Verify that the
reading is above the requirement stated in Section 3.1.5.
4.2.22 Remove resolution target and replace with a
film chip photograph.
4.2.23 Go through normal operations of scanning,
viewing, focusing, changing magnification and so forth. Move
head around to get an idea of latitude in head movement. Make
any other checks that seem appropriate.
4.2.24 Record all comments in Section 6.1.10.
Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
 Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
?
4.2.25 Comments on sections of requirements not
covered by procedure.
1) Section 3.1.2 observable film area. With a grating
aperture of 10 x 10 and the magnifications involved, the film
areas observable are evident without testing. The optical
dimensions are given in the Engineering Report.
2) Section 3.1.10, Film Temperature. There is no
equipment available to measure this parameter. Therefore, the
temperature rise listed in 3.1.10 cannot be actually determined.
Satisfactory operation of the viewer, that is, no damage to the
film, indicates that the temperature rise is within satisfactory
limits.
4.2.26 Sign and date data sheet.
?
Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
 Approved For Release 2002/06/17 : CIA-RDP78B04747A001500020043-7
5.0 PREPARATION FOR DELIVERY
5.1 Inspect the shipping crate for suitability for shipment
of the viewer. The shipping container is to be used for air
freight delivery of the unit. In addition to the viewer, six
spare projection bulbs and five copies of the instruction manual
will be shipped.
6.0 NOTES
? 6.1 Data Sheet for Acceptance Test
6.1.1 Workmanship Comments
0
(signature of inspector
6.1.2 Physical Size
Length Height Width
6.1.3 Electrical Power Consumed (magnification being
changed and lamp at full brightness)
60 cps Volts Amps Watts
6.1.4 Compliance with Requirements 3.1.3
Compliance with Requirements 3.1.8
Approved For Release 2002/06/17 : CIA-RDP78B04747A001500020043-7
 Approved For Release 2002/06/17 : CIA-RDP78B04747A001500020043-7
6.1.5 Compliance with Requirements 3.1.1
Compliance with Requirements 3.1.9
Compliance with Requirements 3.1.11
0
?
6.1.6 Size of exit pupil, compliance with
requirement 3.1.4. Size (inches):
6.1.7 Intensity of Illumination
Microwatts/cm2:
6.1.8 Resolution data 5X lens. Compliance with
requirement 3.1.5.
Resolution 1/mm
H V
On Axis
Upper Right
Upper Left
Lower Right
Lower Left
Average
6.1.9 Resolution Data 50X Lens - compliance with
requirement 3.1.5. On axis resolution: 1/mm
(v) Average:
(h)
Approved For Release 2002/06/17 : CIA-RDP78B04747A001500020043-7
 Approved For Release 2002/06/17 : CIA-RDP78B04747A001500020043-7
6.1.10 Comments on General Viewer Operation:
?
STATINTL
9
6.1.11 Signatures of Participants:
Quality Assurance
Inspector
Project Engineer
Customer Representative
(date)
Approved For Release 2002/06/17 : CIA-RDP78B04747A001500020043-7
 Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
Explanation of formula in Section 3.1.4 and Transmission Value in
Section 3.1.6
ThIC accompanyinc crawing shows the four way overlap which Occurs
in the ti xit pupil plane..
If the exit pupils were small., no
over1z : o=..uld exist; there would an exit pupil matrix of
7-47 exit pupils. Vith the lams aperture size, optical distances
an 6 anc4ular ceviations of the czatine, these overlap to prnc:uce
676 overlappec squares, each mace up of lour exit pupil a?
shown in the erawinea.
In the simple case, Trial #1 (see Figure 1), the intensity of
any of the 1(9 pupils were the function of the transmission in
an order time any other order, such as 3% x 3% - .09%, or
4% x 5% = .2u%. Then .2% x 129 would mean that 34Y. ol the
light flux is eontainec in the 13 x 13 exit pupil plane if all
pupils had this combination.
In this case it becomes more involved. %then the gratin-;; s are
crossed each of- the 727 exit pupils are. mace up in the same way
that the other 169 orvers were. %hen they are overlapped, the
light flux in four of these pupil units are added to provide
the total flux in this .142 x .142 area,
4P
The total. Flux is now a summation of the tollowinc (see Fioure 2):
Say pupil A
then pupil E
anc pupil C
and pupil L
y X
is
order
+4 x +8
is
order
+4 x s?9
is
order
+3 x +8
is
order
+3 x -1-9
Also, only 1/4 of the flux in any pupil is user to n kee up this
overlappec area (x).
Then total flux
a 4x 8 _, 4....x 9 . _+ 3 x
4 4 4
((4 x 8) + (4 x 9) - (3x6) 4_ (3x9)
The transmission is referred to the total flux without a
gratin,, and therefore shoe: the relative intensity of the pupil
units.
The general equation may then be written as
7a x Th) - (i$ x fir) -r (Tc x Tb) f (Tc x Td)
Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
 Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
Pane 2
total trans k.is ion of .142 x .142 ove lappe it
pupil unit. Since transaissiona= are acce'
(because the overlap occurs in the exit pupil
plane), this total transmission is a relative
i ure she ins; v.hat per cent of the total 14
flux ial1inc on the cratinc is c-)ntain#2c j- 4-h4,
11 square.
anc Tc are incivu ua1 orcers such as 3 + 4 in
the y plane and 8 + 9 in the X plane,
The e_uation f-. _ mittee before vas wronc- as a ?7enera7 equation,
It i? valii only where the X ant Y orcers are the same; that is,
when a Point it selectee at, say, X and Y, 0 ant 1, then
previously sub ittec sheet for dra=in-
*; allowec ifl a sins le orc'er as f, min ;.:aum, r
.09% Y;oulc exist .here this order overlapped itself. If the
entire exit pupil as mace up of these units 15.2% of the enemy
4 oulc be in the combined. matrix (.09 x .169). om' when 676
overlapc =nits exist an, the same minimum is alto .ec?, it can
be oc upon in the same way, i.e. 15.2% dividec. by the ?7t==
units give='- .0225% for each of the 676 units. The result of the
previous equation T,1, should always exceed .0225% to }?e above thii-
a1ioa=1 limit.
A 4:1 brightness difference could mean that TT %oulc vary from . 225%
to .1%. $.n example is lister: below.
The overlapped: pupil is mace up of order 3 + 4 in the W direction
and 7 in the }a plane.
Their incivicual transmisions are
Or'-al Transmission ;=b Plane
3 Y
A A 4e'
'ni 7 X
8 6 x
Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
 0
Approved For Release 2002/06/17 CIA-RDP78BO4747AO01500020043-7
Page 3
Then TT = t (.03 x .05) + (.04 x .05) + (.03 x .06)+(.04 x .06)
TT = / .0015 + .0020 + .0018 + .0024
TT = .0077 )O19 = .19%
Then 0.19% of total flux falls in this'.142 x .142 area in
the exit pupil plane.
Approved For Release 2002/06/17 CIA-RDP78BO4747AO01500020043-7
 Approved For Release 2002/06/17 : CIA-RDP78BO4747AO01500020043-7
$ r--' - - ------ DATE---------- -- SUBJECT---------- +; SHEET NO.---------- OF...........
- a
BY.---------- DATE ------------
STATINTL
JOB NO.
-----
.w1aI--------------------------------------------------
OuER LAP ..4PPRQi C;t
ST A,DARO METH 0 A>
o --Release 2.002/ NIT i~-RDP78BQ4747A0 1500024Q