MAINTENANCE MANUAL FOR THE MINI-CAMERA MODEL I

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04560A007400010037-4
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 30
• Document Creation Date: December 28, 2016
• Document Release Date: July 6, 2000
• Sequence Number: 37
• Publication Date: March 1, 1975
• Content Type: REPORT

Approved For Release 20811V 7g0456OA007400010037-4
00
a.~J /,~N- o 0//75
Approved For Release 2001/08/13 : CIA-RDP78BO456OA007400010037-4
 Approved For Release 2001/08/13 : CIA-RDP78BO456OA007400010037-4
CONFIDENTIAL
NATIONAL PHOTOGRAPHIC INTERPRETATION CENTER
MAINTENANCE MANUAL FOR
THE MINI-CAMERA MODELI
Approved For Release 2001/08/13 : CIA-RD 78AYWth 007400010037-4
NPIC/R-04/75
MARCH 1975
 Approved For Release 2001/08/13 : CIA-RDP78BO456OA007400010037-4
NATIONAL SECURITY INFORMATION
Unauthorized Disclosure Subject to Criminal Sanctions
Class+fied by 009907
of E.0 1 1652, exemption category
Automatically declassif ed on
date rnposstble to dete mine
Approved For Release 2001/08/13 : CIA-RDP78BO456OA007400010037-4
 Approved For Release 2001/08/13 : CIA-RDP78BO456OA007400010037-4
CONFIDENTIAL
NATIONAL PHOTOGRAPHIC INTERPRETATION CENTER
MAINTEIVANpqL FORTHE MINI-CgnryERA MODEL I
Reverse side blank
CONFIDENTIAL
NPIC/R_04/y5
Approved For Release 2001/08/13 : CIA-RDP78BO456OA007400010037-4
 Approved For Release 200dONtSDEW-RDP78B04560A007400010037-4
TABLE OF CONTENTS
1
INTRODUCTION . . . ? ? ? ? ? ? ? ? ? ' ' ' '
LIST OF EQUIPMENT . . ? ? ? ? ? ? ? ? ? ' ' ' , 3
EQUIPMENT USE, MAINTENANCE, AND 4
ADJUSTMENT . . . . . . . . . . . ?
Camera Body . . . ? ? ? ? ? ? ? ? ? ' '
4
250-Exposure Motorized Back . . .
5
250-Exposure Film Cassettes . . . . . . . . . . .
Batteries and Battery Checker .
6
Pistol Grip . . . . . . . . . . . . . . . .
6
V iewscope s . . . . . . . . . . . . . . . . . . .
Lenses . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . ' . . . . 8
Focus Scales . . . . . . . . . . . . . . . . 10
Focus Control . . . . . . . . . . . . . . . . . 1 0
11
Adjustment of Focus Control . . .
11
Lens Use at Close Conjugates . . . . . . . . .
Lens Cleaning Aids . . . . . . . . . . . . . . . 13
. . . . . . . . . . . . . . . . . . 13
Focus Calibration . . . . . . . . . . . . . . . . . 13
15
Equipment Operating Manuals . . . . . . . . .
, 15
Attache Case . . . . . . . . . . . . . . .
15
Authorized Maintenance Support . . . . . . . . . . .
Approved For Release 2001/OLJ&Fq&EiiqQa?B04560A007400010037-4NPIC/R-04/75
 Approved For Release 20011?&k*l ?4WL78B04560A007400010037-4
TABLE OF CONTENTS (Continued)
Page
FIELD FOCUS TESTS . . . . . . . . . . . . . . . . . . . 18
Static Focus Tests . . . . . . . . . . . . . . . . 18
Hand-Held Tests . . . . . . . . . . . . . . . . . 20
PERFORMANCE DATA . . . . . . . . . . . . . . . . . . . 20
Lens Field-of-View and Resolution . . . . . . . . . 20
Field-of-View for Viewscopes . . . . . . . . . . . 22
Full-Field Target Area Framing . . . . . . . . . . 23
SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . 23
Approved For Release 20O8Wj IA-ApP78B04560A007400010037-4 NPICIR-04175
 Approved For Release 2001/QJNFtgfU fRUB04560A007400010037-4
LIST OF ILLUSTRATIONS
Figure
Caption
Page
1 Mini-Camera Packaged in Attache Case . . . . . . .
7
2 Mini-Camera Components . . . . . . . . . . . . .
7
3 Viewscopes, 7X and 4X . . . . . . . . . . . .
9
4 Lenses, 180mm f2.8 and 55mm f3.5, . . . . . . . .
9
With Focus Scales, Magnifiers, and
Focus Controls
5 Focus Scale and Magnifier . . . . . . . . . . . .
12
Page
2 Precision Focus Settings and Depth-of- . . . . . . 16
Field for Intermediate Values of Range
to Target, Using the 55mm f3.5 Micro-
Nikkor Lens at Maximum Resolution
3 Precision Focus Settings and Depth-of- . . . . . . 17
Field for Intermediate Values of Range
to Target, Using the 180mm f2.8 Auto-
Nikkor Lens at Maximum Resolution
4 Best-Frame Resolution Goals and Field-
of-View for 55mm and 180mm Lenses
5 Field-of-View for 4X and 7X Viewscopes . . . . . . 22
Reverse side blank
_V.
Approved For Release 2001/qMAp PAIL8B04560A007400010037-4vpIC/R-04/75
 Approved For Release 2001/1i6NZ78B04560A007400010037-4
There are three types of manuals for the mini-camera
model I system:
1. Technical Manual--NPIC/R-10/74. This
contains general technical information
and operating instructions.
2. Maintenance Manual--the present document.
This contains detailed information on
the units which make up the system and
on their maintenance and adjustment,
particularly with regard to the special
modifications provided by the system
contractor. Also included is informa-
tion on calibration and field tests and
typical performance data.
3. Individual Equipment Manuals. These
contain detailed information as furnished
by the original manufacturer on individual
equipment items.
As stated in the Technical Manual, the ability of the
system to deliver high resolution is dependent upon the
operator's full compliance with all rules and instructions.
Included in this maintenance manual is information on field
testing of:
1. Static performance of the hardware.
2. Dynamic performance of the total
system including the operator.
These tests include the use of resolution targets in the field-
of-view, providing a means of determining whether focus cali-
bration has shifted and/or system performance has been de-
graded. System performance data is included.
Comments and queries regarding this manual or the s stem 25X1A
cribed are welcome. They may be directed to
overnment code 143, extension 2476, or gray line ex en-
sion 21 (external number: area code 703, 351-2476).
Reverse side blank
-1-
Approved For Release 2001 /08 FC AIB04560A007400010037-4NP1C/R-04/75
 Approved For Release 2001 /C AblFtR JWIU p8B04560A007400010037-4
LIST OF EQUIPMENT
The mini-camera system (Figures 1 and 2) includes the
following items:
1. Camera body, Nikon F, black.
2. 250-exposure motorized back, Nikon,
individually fitted to the camera body and
noninterchangeable unless refitted.
3. Four 250-exposure (33-foot) film cassettes.
4. Pistol grip, Nikon Model 41, with trigger,
microswitch, and two integral connecting
cords.
5 . Battery pack with eight alkaline " C "
cells and 44-inch cord.
6. Battery checker, Micronta 22-100.
7. Viewscope (sight) 4X, Swift Huntscope Model
722, modified by the addition of a mount
and individually boresighted to the camera
in the same system.
8. Viewscope (sight) 7X, Spiratone 350mm
Teletach, modified by the addition of heavy
crosshairs and a mount and individually
boresighted to the camera.
9. Lens, 55mm-focal-length f3.5, Auto -Micro-
Nikkor-P, modified by the addition of
accurizer scales, magnifier, and worm-drive
focus adjuster, with M-2 extension ring for
use of the lens at 1:1 conjugates.
10. Telephoto lens, 180mm-focal-length f2.8,
Auto-Nikkor-P, modified by the addition of
accurizer scales, magnifier, and worm-drive
focus adjuster.
11. Blower brush, lens cleaner fluid, and lens
cleaning paper (50 sheets).
Approved For Release 2001708$1DEI IA P78B04560A0074000100 ~16/R-04/75
 Approved For Release 20EU9 j RIh*DP78BO456OA007400010037-4
13. *Focus calibration sheet.
14. *Operating manuals for camera, motorized
back, pistol grip, and lenses and instruc-
tions for setting the combination lock on
the attache case.
15. Attache case, Samsonite Classic 100, equipped
with combination lock and foam lined.
The weight of the mini-camera system is 19 pounds.
EQUIPMENT USE, MAINTENANCE, AND ADJUSTMENT
CAMERA BODY
For motorized use the camera body is assembled into the
250-frame back. For conventional, nonmotorized use (camera is
less bulky but also less capable) the camera body is removed
from the motorized back (consult the Nikon manual for data on
the motorized back) and installed in the original back, which
is stowed beneath the camera in the attache case.
250-EXPOSURE MOTORIZED BACK
The 250-exposure back for the Nikon F camera is individ-
ually fitted to the camera body with which it is to be used.
Malfunctions in the shutter or film transport may result if
the back is used with the wrong camera. If such malfunction
occurs with a properly matched camera body and back, they
should be returned to the nearest Nikon maintenance center for
adjustment.
*In the space -Behind the foam liner in the top half of the
attache case.
Approved For Release 2001/08/13 : CIA-RDP78B04560A0074000100377#,IC/R-04/75
CONFIDENTIAL
 Approved For Release 2001L98//1iiER 78B04560A007400010037-4
Damaged or improperly loaded film cassettes can cause
total mission failure by preventing normal film transport.
New cassettes should be checked to determine that the
inner shell rotates freely in the outer shell. If not, the
interference can normally be eliminated by holding the outer
shell in the left hand and rotating the inner shell inside the
outer shell, back and forth through the interference area,
under pressure of the right hand. Cassette parts should then
be cleaned with a damp rag to prevent metal dust from getting
into the camera.
Before loading with film, cassettes should always be
checked for free rotation as above. Damaged cassettes should
not be used.
In assembling and closing the cassette after loading it
with film, it is important to turn the inner shell clockwise
only to the latching position. Turning it too far will leave
it unlatched or will capture a full turn of film between the
inner and outer shells.
In installing the cassettes in the 250-exposure back, it
is important to carefully follow the manufacturer's directions,
making sure the cassette snaps into place with the index mark
on it properly lined up. If the cassette can be rotated in
its socket, it is not installed properly. (Pressure exerted
by foam pads inside the rear cover prevents such rotation when
the rear cover is closed.) If a problem becomes apparent at
any time during the process of installing the cassettes and
checking for proper operation, start over at the beginning.
The 250-frame motorized back can also be used with com-
mercially available 36-exposure rolls of High-Contrast Copy or
other films. This involves releasing two thumb latches, remov-
ing the camera body from the motorized back and loading the
36-exposure roll of film in normal fashion (refer to the Nikon
motor drive and camera body manuals), and then reinstalling
the camera body in the motorized back and operating the same
controls as with a 250-frame load.
Approved For Release 2001/08-1 l8 K18B04560A007400010037-*PIC/R-04/75
 Approved For Release 20B16W16ERl)- P78B04560A007400010037-4
The battery pack carries eight alkaline "C" cells. If
alkaline cells are unavailable, ordinary carbon-zinc dry cells
may be used. However, alkaline cells have longer life, more
constant voltage, and better low-temperature performance.
Batteries should be checked after returning from a mission,
and replaced if weak. New batteries should be checked,
especially if purchased overseas. Battery life depends on the
duration and temperature of prior storage and on the mission
conditions. The estimated life of "C" batteries used in the
250-frame motorized camera is as follows:
Carbon-Zinc
Alkaline
Continuous use
1 roll
3-4 rolls
(250 frames)
(750-1,000
frames)
Intermittent use
5-8 rolls
10-20 rolls
(1,250-2,000 (2,500-5,000
frames) frames)
Use of the pistol grip is essential to support very long
lenses which might be used with the mini-camera. With the
55mm and 180mm lenses initially furnished, use of the pistol
grip is optional. To avoid losing the top screw which serves
as a quick-release stud, it should always be locked in the top
of the pistol grip or screwed into the tripod socket of the
camera lens.
Two monocular sights or viewscopes are furnished
(Figure 3). The 4X Swift Huntscope is normally used at short
range and in conditions where the target moves at a high angu-
lar rate relative to the camera. The 7X Spiratone 350mm
monocular is used at long range, and especially with longer
lenses (180mm and longer).
Approved For Release 2001/08/13 : CIA-RDP78BO456OA007400010037-4
CONFIDENTIAL NPIC/R-04/75
 Approved For Release 2001 /0 f NmF36B04560A007400010037-4
FIGURE 1. MINI-CAMERA PACKAGED IN ATTACHE CASE
FIGURE 2. MINI-CAMERA COMPONENTS
Approved For Release 20 IP06/' AM LZDP78B04560A007400010037-4
NPIC/R-04/75
 Approved For Release 2001/08/13 : CIA-RDP78B04560A007400010037-4
CONFIDENTIAL
The 4X sight is fixed focus, and is in focus at distances
of 50 feet, or greater. The 7X sight has a focusing objective
lens and can be focused at any range. The calibration on the
objective lens can be ignored, the operator focusing visually
through the sight.
Each sight has been fitted with a mount and boresighted
to a line-of-sight parallel to the optical axis of the camera.
The mount slides over dovetail ways below the camera rewind
handle. The mount is fitted to the camera by tightening a wing
bolt to pinch the mount so that it slides snugly onto the dove-
tail ways. If the ways should wear, the fit can be restored
by tightening the wing bolt a small amount.
Reasonable care should be taken in installing and
removing the sight, in order to avoid putting excessive torque
on the dovetail ways of the camera.:
Caution: In normal use of a through-the-lens
viewfinder camera like the Nikon F, it is impossible
to leave the lens cap on inadvertently during
photography. In using the mini-camera with a sight,
there is a possibility of leaving the lens cap on.
The user should develop a routine and a checklist
to prevent this from happening.
Description
Two lenses are furnished (Figure 4). The 55mm-focal-
length f3.5 Auto-Micro-Nikkor lens gives outstanding perform-
ance at long and"short ranges.* The 180mm-focal-length f2.8
Auto-Nikkor lens has an advantage of a 3.3 times greater focal
length, although image-plane resolution is less than for the
*This lens was originally developed for close conjugate work.
It can be used down to a 1:2 image-to-object ratio or down to
1:1 with the M-2 extension ring furnished with it. The optical
design is such that the lens performs extremely well at long
range as well as at short range.
CONFIDENTIAL { NPIC/R-04/75
Approved For Release 2001/08/13 : CIA-RDP78B04560P(007400010037-4
 Approved For Release 2001 /dMNFlc AC ffiPt.8B04560A007400010037-4
FIGURE 3. VIEWSCOPES, 7X AND 4X
I~
FIGURE 4. LENSES, 180MM F2.8 AND 55MM F3.5, WITH FOCUS SCALES,
MAGNIFIERS, AND FOCUS CONTROLS
-9-
Approved For Release 2001 /Q' FiS1 Xj8B04560A007400010037-4PIC/R-04/75,
 Approved For Release 20 //3/i Qj MjDP78B04560A007400010037-4
55mm lens. For long-range photography the net effect of these
two factors on target resolution is to give an advantage of
better than 2 to 1 in favor of the 180mm lens if image smear
is kept under control.
Focus Scales
Both lenses are equipped with precision photo-etched
invar focusing scales. The stator scale has 40 equal divisions
-- 20 on either side of zero-- at 0.004 inch per division.*
The focus ring (rotor) of the 55mm lens is graduated at 10,
20, 50, 100, 200, 500-foot, and infinity-range values. The
180mm lens rotor is graduated at 50, 100, 200, 500, 1,000,
2,000 feet, and infinity. The scales are viewed through a
15X, f1.4, coated achromat magnifier permanently mounted to
the lens barrel. In viewing the scales while focusing, the
operator should use care to center his eye over the magnifier.
Otherwise a parallax error of one-half to one division is
possible. If it should become necessary, the scales can be
cleaned by the blower brush or by a cotton 'IQ-Tip'' dipped
in alcohol, the operator taking care not to scratch the scales.
Focus Control
Focus is controlled by manually turning a spring-loaded
worm drive** on the lower side of the lens while observing
the focus scales through the magnifier. When the focus has
been set, the worm drive locks the rotor in position against
accidental movement.
*0.004 inch on the circumference of the lens represents a
0.00068-inch axial focus shift for the 55mm lens and a
0.00080-inch axial focus shift for the 180mm lens.
**For a left-handed photographer the worm and its flex shaft
and knob can be reversed; care must be taken to replace the
shims in their same positions under the flat spring which
controls the pressure of the brass worm against the curved
stainless steel rack. Epoxy should be applied to hold the
screws in place. If the worm drive is reversed, clockwise
rotation of the worm drive will move the rotor from left to
right.
Approved For Release 2001/08/13 : CI ALDP78BO456OA007400010 3 C/R-o4/75
 Approved For Release 2001 /CWWII E 1RI l78B04560A007400010037-4
Caution: In order to avoid the effects of back-
lash in the threads internal to the lens, it is
necessary always to start with the rotor scale to
the extreme left (L-20 on the stator scale) as
viewed through the magnifier, and turn the worm
drive knob counterclockwise, bringing the proper
rotor range mark to the calibrated stator index
without overshoot. In case of overshoot, start
again from the extreme left position.
Adjustment of Focus Control
At the time of original assembly the pressure of the
brass worm against the curved stainless steel rack (Figure 6)
was adjusted by the use of shims under the flat steel spring
which presses on the worm shaft. If the pressure of the worm
against the rack should be reduced, the worm drive will have
backlash and may slip a thread at some point in its travel.
If the pressure of the worm against the rack should be
increased, it will become difficult to turn the focus control
knob. In either case the problem may be corrected by remov-
ing the Phillips-head screw(s) which hold the U-shaped flat
spring and cover plate in place (keeping track of the position
of the shims) and reshimming to the desired pressure (that
which allows free-turning operation over the full length of
the scale without backlash). When the proper combination of
shims is in place, the Phillips-head screw(s) should be fixed
in place with epoxy glue. If the grease on the rack and worm
becomes dirty, it should be removed with a solvent. The worm
and rack can be relubricated by applying a strip of silicone
grease to the rack.
Lens Use at Close Conjugates
To use either lens at distances closer than the minimum
calibration, turn the focus control knob clockwise until the
worm disengages from the rack. Then the focus ring may be
rotated in the normal fashion to focus at any distance within
the scope of the lens. To return the focus ring to the
control of the worm drive, turn the focus ring until the rack
contacts the worm. Then maintain a slight pressure between
the rack and the worm while rotating the focus control knob
counterclockwise until the worm and rack engage.
Approved For Release 2001 /0 : RE?'d?B04560A007400010037-4NPIC/R-04/75
 Approved For Release 20OMFILE kDP78B04560A007400010037-4
f "0 1 so mm 822689
12
FIGURE 5. FOCUS SCALE AND MAGNIFIER
cr a
FIGURE 6. FOCUS-CONTROL WORM DRIVE
- 12-
Approved For Release 28 1 61N%EDP78B04560A007400010037-4
NPIC/R-04/75
 Approved For Release 2001/08/13 : CIA-RDP78BO456OA007400010037-4
CONFIDENTIAL
Lens Cleaning Aids
How do you clean an optical surface? Carefully! The
55mm and 180mm lenses, both sights, and the magnifiers on
both lenses have coated optical surfaces which can be scratched
in the process of cleaning. Dusty or smudged areas on the
surfaces of the lenses and viewscope optics will be out of
focus but will have little effect on imagery unless the sun
is shining directly on the dusty or smudged surfaces. For
this reason it will normally be better to leave minor smudges
untouched. Dust can be blown and/or brushed off optical
surfaces with the blower brush. Since most dust will scratch
glass and lens coatings, the blower brush should always be
used as the first step in.cleaning. If necessary to go beyond
this step, a drop or two of lens cleaner on lens paper can be
used to remove smudges. The lens paper should be formed into
a mushroom shape and held by the stem. Under no conditions
should the finger be used to apply pressure to the lens sur-
face directly through a layer of lens paper.
Each mini-camera system is tested by the system contrac-
tor to determine the focus settings that will give maximum
resolution. The focus calibration sheet* indicates the rotor
and stator scale readings for best performance of the 55mm
lens at target distances of 50 feet, 500 feet, and infinity,
*In the space behind the foam liner in the top half of the
attache case.
Approved For Release 200i 4 D@FATI ?78BO456OA00740001003-IX IC/R-04/75
 Approved For Release 2001/08/13 : CIA-RDP78BO456OA007400010037-4
Approved For Release 2001/08/13 : CIA-RDP78BO456OA007400010037-4
 Approved For Release 20e1%1?jENIA{WP78B04560A007400010037-4
and of the 180mm lens at 50 feet, 1,000 feet, and infinity.
The 55mm lens will normally be used at either infinity or
50 feet, and the focus calibrations discussed above will be
sufficient for such normal operation. For situations involv-
ing the 55mm lens where the range is too short to use the
infinity focus calibration, and where the range can be deter-
mined precisely, the precision focus settings of Table 2 can
be used. Similarly, Table 3 gives precision focus settings
for the 180mm lens. These data indicate that the 180mm lens
should be focused one-half stator division to the left of the
stator calibration for infinity, if the targets are between
4,500 and 20,000 feet away; one stator division to the left
of the stator calibration for infinity, if the targets are
between 3,000 and 15,000 feet away; and one and one-half
stator divisions to the left of the stator calibration for
infinity, if the targets are between 2,300 and 5,600 feet
away.
EQUIPMENT OPERATING MANUALS
Manufacturer's manuals are provided* for the camera
body, 250-exposure motorized back, pistol grip, and lenses.
Instructions are also provided* for setting the combination
lock on the attache case.
ATTACHE CASE
The system is contained in a Samsonite Fiberglass Classic
100 attache case with combination lock and instructions* for
setting the combination. If needed, replacement foam is
available from Ikelheimer-Ernst, 601 West 26th Street, New
York, N. Y. 10001; area code 212, 675-5820.
AUTHORIZED MAINTENANCE SUPPORT
Depending on the nature of the malfunction or repair
requirement, maintenance may be performed in the field or by
either the original equipment manufacturer or the system
contractor who made equipment modifications and assembled and
tested the final hardware.
*In the space behind the foam liner in the top half of the
attache case.
Approved For Release 2001/u$b14F1 R18B0456OA007400010037-&PIC/R-04/75
 Approved For Release 2001 /4 DKiFI?I& JR18B04560A007400010037-4
Table 2. Precision Focus Settings and Depth-of-Field for
Intermediate Values of Range to Target, Using the 55mm f3.5
Micro-Nikkor Lens at Maximum Resolution (This data is for use
where range to target is known -- that is, within the depth-
of-field limits shown.)
Focus Settings (55mm Lens)
Depth-of-Field*
(ft)
Nominal
Range
Rotor
Index
Number of Divisions to Move
Rotor Index to Left of
Near
Field
Far
Field
(ft)
(ft)
Stator
Calibration
Limit
Limit
50
0 47
54
55
1 52
60
61
2 57
67
68
3 64
76
76
4 71
85
86
5 80
97
100
100
0 91
113
120
1 105
138
150
2 124
184
200
200
0 160
268
300
1 218
440
500
500
0 320
840
840
1/2 420
1
000
co
Co
0 840
,
Co
*There is an approximately 5% resolution loss at the near
and far limits of the field.
Approved For Release 2Q jQ#f g y DP78B04560A00740001097IC/R-04/75
 Approved For Release 2001 1 ?PW P MF8BO456OA007400010037-4
Table 3. Precision Focus Settings and Depth-of-Field for
Intermediate Values of Range to Target, Using the 180mm f2.8
Auto-Nikkor Lens at Maximum Resolution (This data is for use
where range to target is known -- that is, within the depth-
of-field limits shown.)
Focus Settings (180mm Lens)
Depth-of-Field*
(ft)
Nominal
Range
Rotor
Index
Number of Divisions to Move
Rotor Index to Left of
Near
Field
Far
Field
(ft)
(ft)
Stator Calibration
Limit
Limit
500
0 470
530
550
1 510
590
620
2 570
680
710
3 650
780
840
4 750
930
1,000 1,000
0 880
1,140
1,250
1 1,080
1,480
1,750
2 1,380
2,100
2,000 2,000
0 1,600
2,650
3,500
1 2,300
5,600
5,000
1-1/2
(1
division 3,000
from oo )
15,000
9,000
2
(1/2 division 4,500
from oo )
20,000
0 9,000
Co
*There is an approximately 10% resolution loss at the near
and far limits of the field.
Approved For Release 2001 /f' pl?l f g 8B04560A007400010037-g pJC/R-04/75
 Approved For Release 200DOWMEICTAA%DP78B04560A007400010037-4
In view of the importance of maintaining system optimiza-
tion, it is recommended that only minor maintenance and
adjustment be attempted in the field (for example, adjustment
of focus control, as described on page 10 of this manual).
Problems with the pistol grip, battery pack, motorized back
and cassettes, camera body, or shutter may be referred to
authorized Nikon maintenance centers, preferably those in
the US listed here: EPOI, 362 Stewart Avenue, Garden City,
N. Y. 11530; EPOI, 7000 North Ridgeway, Chicago, Ill.
60645; EPOI, 501 Folsom Street, San Francisco, Calif. 94105;
EPOI, 355 South Douglas Street, El Segundo, Calif. 90245.
Problems involving the lenses, the sights, their modifications,
mum system performance should be referred to
government code 143, extension 2476, or gray line ex-
tension 3821 (external number: area code 703, 351-2476).
FIELD FOCUS TESTS
The mini-camera system is designed to provide a means
by which the focus calibration and resolution performance
of the system can be verified at any time in the field.
Because focus accuracy is critical to system performance
and may change as a result of use, provision has been made for
field focus calibration by means of a through-focus run,
according to the following procedure:
1. Load the camera with film and mount it on a
tripod from which a 30-pound weight is hung
for stability. Lock the reflex mirror in the
up " position. Mount the 55mm lens on the
body and set the lens for f3.5 at 1/1000
second.
2. Tape a wall target* to an east-facing tripod
(or wall) so that it will be illuminated by
the direct early morning sun.
3. Use the sight to point the camera so the target
is in the center of the field.
*In the space behind the foam liner in the top half of the
attache case.
Approved For Release 20891 ErVIc-P78B04560A0074000100O7t/R-04/75
 Approved For Release 2001/OoP?]F 118B0456OA007400010037-4
4. Starting from a position well beyond L-20,
turn the focus control knob counterclockwise
until the 50-foot rotor index mark is at L-20
on the stator.
5. Expose one frame each with the 50-foot rotor
index mark at L-20,, L-19, etc., until the
third division short of the 50-foot stator
calibration mark (usually L-1, -2, -3, -4,
or -5 for the 55mm lens and higher values for
the 180mm lens), as specified on the focus
calibration sheet. Expose three frames each
for the next seven successive stator divi-
sions. Expose one frame for each of the
remaining stator divisions, ending at ''0 '' .
In case of overshoot at any division, go back
to the start position and rotate the focus
control knob counterclockwise again to the
desired point. This action eliminates the
effect of backlash in the internal focus
thread of the lens.
6. When the film has been processed, the target
images will be read out to determine the best
resolution in both directions for each frame.
Plotting a curve of resolution in lines per
mm vs rotor position will show the position in
lines per mm (consult Table 1 for the wall
target calibration).
7. A similar procedure is followed with the
180mm lens.
These static focus test can be run at any time when there
is reason to believe the focus of the camera/lens combination
may have shifted. To aid in determining the cause of below-
standard mission imagery, it is recommended that an abbrevi-
ated through-focus test using the first 15 to 20 frames of
the cassette be run prior to each mission, so that when the
film is processed, the focus calibration can be validated for
that mission.
Approved For Release 2001 /OVNfiaEEN lU) V8B04560A007400010037-4pic/R-o4/75
 Approved For Release 29M MIPS ALTMKDP78B04560A007400010037-4
Caution: After any through-focus run be sure to
reset the focus for the expected operational use,
starting from a position well beyond L-20 and
turning the focus control knob counterclockwise
until the desired rotor index mark is at the stator
calibration point.
The ability of an operator to hold the camera steady can
be verified at the time of the static focus test by having
him use the camera, hand-held, to photograph the wall target
at a 50-foot range, in one or more 15- to 30-frame bursts.
The ability of an operator to track a target from a moving
vehicle can be verified by having him photograph the target in
a 30- to 40-frame burst while being driven past it. A speed
of 2.5 miles per hour at a range of 50 feet simulates the
angular tracking rate of an auto traveling 25 miles per hour
at a 500-foot range or of an airplane at 100 miles per hour
at a 2,000-foot range.
The following performance data has been measured and/or
computed for the optical components of the mini-camera I as
an aid to the selection of lenses for any given mission.
Table 4 indicates the field-of-view for each lens as a
function of range. It also indicates the resolution goals for
the best frame out of one or more bursts. The ability of the
system to deliver such resolution can be validated by static
focus tests discussed in previous paragraphs. Getting similar
performance on occasional frames in hand-held tests is evidence
of full operator proficiency.
Approved For Release 20 1N>F/ffE ItTAA1