A VARIABLE ANAMORPHIC EYEPIECE FOR USE WITH THE(Sanitized) ZOOM 70 MICROSTEREOSCOPE

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04747A002600030039-9
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 10
• Document Creation Date: December 28, 2016
• Document Release Date: May 31, 2002
• Sequence Number: 39
• Publication Date: April 8, 1964
• Content Type: RS

I Approved For Release 2002/06/17 : CIA-RDP78BO4747AO02600030039-9
April 8, 1964
Printed in L.S.A.
A VARIABLE ANAMORPHIC EYEPIECE
FOR USE WITH THE
ZOOM 70 MICROSTEREOSCOPE
Declass Review by
NIMA/DOD
STAT
STAT
Approved For Release 2002/06/17 : CIA-RDP78BO4747AO02600030039-9
 Approved For Release 2002/06/17 : CIA-RDP78B04747A002600030039-9
TABLE OF CONTENTS
Page
1.0
Introduction
1
2.0
Description of Breadboard
1
3.0
Anamorphic Optical System
1
4.0
Description of Anamorphic Adapter
5
4.1 Optical Description
5
4.2 Mechanical Description
5
5.0
Eyepiece Optics
8
6.0
Simplified Approach
8
LIST OF ILLUSTRATIONS
1
Breadboard of Anamorphic Lens System, Side View
2
2
Breadboard of Anamorphic Lens System, Top View
3
3
Anamorphic Lens Schematic
4
4
Variable Anamorphic Adapter
6
5
Image Erector
7
6
Anamorphic Adapter - Alternate Configuration
9
ii
Approved For Release 2002/06/17 : CIA-RDP78B04747A002600030039-9
 Approved For Release 2002/06/17 : CIA-RDP78B04747A002600030039-9
1.0 INTRODUCTION
This proposal presents the technical details for the design and
fabrication of a matched pair of variable anamorphic eyepiece at-
tachments for the zoom 70 Microstereoscope. The
proposed stereomicroscope eyepiece adapter will provide the nec-
essary rectification over the small fields of view which are cov-
ered at the magnifications required. The variable anamorphic lens
will provide a variable 3X distortion in X and Y. The same basic
anamorphic adapter is utilized to provide four ranges. A lOX eye-
piece will provide 5X to 15X, a 15X eyepiece will provide 7.5X to
22.5X, a 20X eyepiece will provide lOX to 30X, and a 30X eyepiece
will provide 15X to 45X differential anamorphic ranges. No modi-
fications to the Zoom 70 power pod is required when inserting and
using the anamorphic adapters. Each eyepiece adapter is rotatable
through 360 degrees, thereby providing complete freedom in the or-
ientation of the anamorphic distortion. The maximum extension of
the present power pod receptacles will be 4.5 inches. The optical
center line will be offset so that the original Zoom 70 eye sepa-
ration range can be achieved.
2.0 DESCRIPTION OF BREADBOARD
In order to establish the feasibility of the proposed system a
breadboard was set up and evaluated. The breadboard utilized t'wn
100mm focal length cylindrical lenses which were previously uti-
lized in a successful anamorphic system for a projector which re-
corded photographic subtitles on cinemascope motion picture film.
This system reduced an area four inches in diameter 10 times with
a 2:1 anamorphic squeeze.
The breadboard (Figure 1 and 2) utilized a 40mm microscope objec-
tive to project a USAF test pattern through the two cylindrical
lenses. A 3X anamorphic scale change was achieved and no color,
aberration, or distortion was evident during visual inspection.
A resolution of 200 lines per millimeter was resolved.
Similar lenses have been scaled down and utilized in the proposed
design.
3.0 ANAMORPHIC OPTICAL SYSTEM
An optical system that will give different magnification along X
and Y axes is illustrated in the following sketch.
STAT
Approved For Release 2002/06/1 i : CIA-RDP78B04747A002600030039-9
 Approved For Release 200W 1i.7 : CIA-RDP78BO4747AO02600030039-9
Next 1 Page(s) In Document Exempt
Approved For Release 2002/06/17 : CIA-RDP78BO4747AO02600030039-9
 Approved For Release 2002/06/17 : CIA-RDP78BO4747AO02600030039-9
L1
La
Fa Fl
2d d -~-JI~
Figure 3 ANAMORPHIC LENS SCHEMATIC
F2
Ll is a positive cylindrical lens, preferably a piano convex lens
indicated by I L2 is a negative cylindrical lens, preferably a
piano concave one, indicated by I . Both lenses are of equal
focal length. The focal points of the lenses are indicated in the
sketch.
The original image projected by the microscope objective lens will
be the arrow 0. By the interposed cylindrical lens Ll, zero will
he projected into another plane and appear as a smaller arrow 1.
This image is taken up by the negative cylindrical lens L2 and im-
aged back to the original image plane as a still smaller arrow 2.
This action takes place in a plane which is defined through cyl-
inder axis of the two cylindrical optical elements. The cylindri-
cal axis of these two elements must be parallel. Since there is
no optical effect in a plane perpendicular to the thus defined
plane, we have different magnifications along the X and Y axes.
A circle viewed through this arrangement will appear as an ellipse,
a square as a rectangle. If no optical effect is desired the two
cylindrical elements are positioned such that the cylindrical sur-
faces touch each other. In this case the two lenses represent a
piano parallel plate with no effect upon the magnification of the
system.
The ratio in which the magnification Mx and My differ is a function
of D, (the distance between the cylindrical lenses). In order to
keep image 0 and image 2 sharp in the same plane, Li must move a
distance 2d. L2 must move d in the opposite direction. The direc-
tion of the cylinder axis of both elements must be kept parallel
during the motion.
- 4 -
Approved For Release 2002/06/17 : CIA-RDP78BO4747AO02600030039-9
 Approved For Release 2002/06/17 : CIA-RDP78BO4747AO02600030039-9
By turning the whole assembly around the optical axis, the direc-
tion of highest magnification will change. Any orientation for
the variable magnification may thereby be selected.
4.0 DESCRIPTION OF ANAMORPHIC ADAPTER
4.1 OPTICAL DESCRIPTION
Figure 4 shows the proposed design of the Variable Anamorphic
Adapter. Cylindrical lenses of 75mm focal length are arranged in
accordance with the previous discussion, illustrated in Figure 3.
This assures the required action to provide a 3X anamorphic range.
The positive lens travels two inches into the microscope tube,
while the negative lens moves one inch in the direction of the
eyepiece. In order to compensate for the field loss caused by
the anamorphote cells and fill the field at the eyepiece for the
lower magnifications, a relay system is inserted between the neg-
ative lens and the eyepiece. This relay lens provides an addi -
tional 1.5X magnification. Figure 4 shows a folded mirror system
to decrease the over-all length of the adapter. However, a mirror
system will provide an inverted image at the eyepiece. If this
is not desirable, Figure 5 illustrates a porno-prism image erector
which could replace the mirror system in order to provide a cor-
rect image at the eyepiece.
4.2 MECHANICAL DESCRIPTION
Mechanically the whole system can be rotated around the optical
axis by means of a lever to align axis of maximum magnification
to X or Y. The position of the plane of maximum ma reification can
be seen from the position of the operating lever. This lever will
be located on the image erector housing.
Another knob also located at the erector housing controls the
squeeze of the anamorphic system. By this knob tube T2 is rotated
thus moving celll and cell.2 in opposite directions to change the
distance between the cylindrical lenses. The knob will be coupled
to the tube. Helical slots with a 2:1 pitch ratio will maintain
the correct lens position throughout the anamorphic magnification
range. Two pins in each cell for Ll and L2 reach through the hel-
ical slot in tube T2 and straight slot in tube Ti. As tube T2 is
turned, (while Ti is kept in place) the two cells will follow the
helical slot and move in opposite direction to give the anamorphic
effect. The straight slot in tube Ti will keep the two cells and
thus the two cylindrical lenses parallel.
- 5 -
Approved For Release 2002/06/17 : CIA-RDP78BO4747AO02600030039-9
 Approved For felease 2002/06/17 : CIA-RDP78BO474\002600030039-9
t -m rurc KU i hi 1N1.
ZOOM 70 Tl)BE~' i
(G. F?E)
SQUEEZE CONTROL
~ ",jilt i ._.n CELL #Z
SQUEEZE
CYL. LENS #1
CEL.#
THEORY OF OPERATION
TURNING TUBEnZ INSIDE TU5E"1 CONTROLS THE
SQUEEZE RATIO.
TURNING TUBE"1 ALIGNS TWO (Z) MAGN%FICATION
AXES WITH VIEWED OBJECTS
Appo ed For Re 2Q 2/06( 7 < - 7$ IZA002600030039-9
'OLDING MIRROR
 Approved For Release 2002/06/17 : CIA-RDP78B04747A002600030039-9
RELAY LENS
IMAGE ERECTOR
EYEPIECE
Figure 5
- 7 -
Approved For Release 2002/06/17 : CIA-RDP78B04747A002600030039-9
 - Approved For Release 2002/06/17 : CIA-RDP78BO4747AO02600030039-9
5.0 EYEPIECE OPTICS
The basic anamorphic adapter using two 75mm focal length lenses
will be utilized with a 1.5X relay lens and folded light path in
order to fill the exit pupil. through the anamorphic magnification
range. A total of four eyepieces and magnification ranges will
be d. The lOX and 20X eyepiece presently available with
the Zoom 70 Stereomicrescope will be applicable. Two addi-
tional eyepieces, one 15X and one 30X, will be pr.)vided. The
following operational ranges will thereby be possible.
EYEPIECE
MAG. X
MAC. Y
ANGULAR
UX1l
FIELD
ilyH
1 Ox
l ox
15X
-~ 5X
+210
+ 8 ?
2OX
20X
30X
- lOX
+21 ?
+210
15X
15X
22.5X
>7.5X
+21?
+11?
1_. 30X
3OX
45X
-"15X
+210
+21?
The lOX eyepiece presents a problem at the lower magnifications
in normalizing the field of view at the exit pupils. With the lOX
eyepieces an oval to round field of view occurs very quickly at a
1:1 squeeze ratio, and at the 3:1 range presents a diameter along
Y axis of approximately one-third of the full field. This condi-
tion starts occurring with the 15X eyepiece at an anamorphic
squeeze of 1.5X and presents a view in one axis of approximately
two-thirds the full field at the full 3:1 anamorphic range. This
condition' is probably acceptable with the 15X eyepiece, but may
give the operator some difficulty at the lower ranges of the lOX
eyepiece.
6.0 SIMPLIFIED APPROACH
The sole purpose for the relay lens and folded optical system is
to provide an improved field at the eyepiece which does not vis-
ually accentuate the anamorphic action of the field, Figure 6 in-
dicates a simplified system without the relay lens and folded path.
The system also incorporates a 3:1 anamorphic action and will pro-
vide a magnification range from 5X to 30X with properly selected
eyepieces. However, the foreshortening of one eyepiece field of
view with respect to the other occurs at higher magnifications
than a system with a relay lens. It is, however, a much lighter,
simpler, and economical approach to the problem, if the operator
would not consider out-of-round fields of view too serious a detri-
ment.
STAT
- 8 -
Approved For Release 2002/06/17 : CIA-RDP78BO4747AO02600030039-9
 Approved Forfelease 2002/06/17 : CIA-RDP78B0474A002600030039-9
rte-POSITION FOR NlA) IMUM
I SQUEEZE
POSITION FOR
ZERO 3QU EEZE
KID I RL.ED RING FOR
'ROTA-T I NG TUBE -.1
KNURLED RIN C-q FOR
SQUEEZE CONTROL
CYL. LEE Z.
GELD a
THEORY OF OPERATION
TURNING TU E ,E.#Z I NISI DE TUBE ** 1 CONTROLS THE
SQUEEZE RATIO.
TU RNN G TUEEE.'* I AU GN S TWO (a MAC,NIF1 CAT\ON
AXE WITH V1EWEL'y OEJECTS
Figure 6 ANAMORPHIC ADAPTER - ALTERNATE CONFIGURATION
Approved For Release 2002/06/17 : CIA-RDP78BO4747AO02600030039-9