LOMO 35BAS22-2 User manual

LOMO
Anamorphic Unit
35BAS22-2
Instruction Booklet
1. USE OF THE UNIT
Anamorphic Unit 35BAS22-2 is intended for shooting wide-screen color and b/w movies onto 35mm
film using Russian cine cameras with distance between film and shutter of 19mm. The lens is
designed to be used within a temperature range of -30 to +40 degrees Centigrade.
2. SPECIFICATIONS
Basic Characteristics
Value
Focal length, mm
48
Back apical focal length, mm
34.2
Geometrical relative aperture
1:2
Frame size, mm
18.6 x 21.95
Aspect ratio in the middle of the frame
0.5
Close focus distance, m
1
Dimensions, mm:
length
diameter
165
105
Weight, kg
1.6
3. OPTICS, CONSTRUCTION AND OPERATION
3.1. Optics
Optical design of the anamorphic unit 35BAS22-2 (Figure 1) consists of the lens 1 (lens OKS1-50-1,
F=50mm, f/2) and anamorphic attachment 2. The anamorphic attachment consists of two-lens
spherical compensator 3 (elements 4 and 5) and two cylindrical components (6 and 7). The
components of the attachment and the lens are immovable. Lens 4 of compensator 3 is moved
during focusing.
3.2. Construction
The anamorphic unit consists of two assemblies –the lens and the attachment. In attachment body 8
elements 5 and 6 are fixed. Holder 9 with lens 7 is screwed into the body. Shooting distance is set
by rotating ring 10 screwed to holder 12 with element 4 by means of screws 11. Ring 13 is marked
with a shooting distance scale. The lens in the focusing mount is connected to the attachment body
by means of bayonet nut 14.
The lens-focusing mount consists of two bushes 15 and 16, the aperture scale 17, nut 18 and the
mount 19.
To change the focusing mount, unscrew screw 20, loosen screws 21, screw off mount 19, screw in
the corresponding replacement mount, and then tighten screws 20 and 21.
Slider 22 is intended to mount the unit to the camera. Screws 21 and 23 are used to fix the unit after
adjustment.

4. IDENTIFICATION MARKING
Nut 18 is marked with the name of the manufacturer, unit name, focal length of the lens, geometrical
aperture of the unit, and the serial number of the unit (6 digits; first two digits are the year of
production, and the last four digits are the number).
5. MOUNTING TO CAMERA
Adjustment of the unit upon mounting it onto a camera consists of matching the image plane of the
unit with the film plane, and aligning the cylindrical elements of the attachment with the vertical side of
the camera gate aperture.
5.1. Before adjusting the unit, check the factory adjustment by means of an optical bench.
5.2. To match the image plane of the unit with the film plane, mount the unit onto a camera, and place
it in front of an autocollimator (it is advisable to use an autocollimator with lens focal length of 300-
400mm); set ‘infinity’ by means of ring 10; fix a flat mirror (an aluminized one, or a polished metal
plate) in the gate aperture (the polished or aluminized side should face the guides of the gate
aperture); achieve a match of the unit image plane with the film plane by means of nut 18; eyepiece
of the autocollimator should be set to ‘infinity.’ After adjustment, secure nut 18 by means of screws
21.
5.3. To align the cylindrical elements of the attachment with the vertical side of the camera gate
aperture, mount any usual lens onto the camera, and align a vertical line of the focusing magnifier
with the image of some vertical line; then replace the lens with the anamorphic unit taking care to not
move the camera. The image of the vertical line should remain aligned with the vertical line of the
focusing magnifier. If the lines are not parallel, loosen screws 20 and 23 and turn the unit due to gap
between screws 23 and slider 22. Tighten screws 20 and 23 after adjustment.
6. MAINTENANCE
6.1. Protect the unit against shocks, vibration and mechanical damage.
6.2. Remove dust from the lens surface by means of a clean squirrel brush washed in ether and
dried, or other approved lens cleaning means.
6.3. Clean metal parts with clean wiping cloth.
6.4. Use a lens caps to protect the optical surfaces.
6.5. Do not disassemble the unit.
7. STORAGE AND TRANSPORTATION
7.1. The unit should be stored in its packing case at a temperature of +1 to +40 degrees Centigrade,
and at a relative humidity no higher than 80% at +25 degrees Centigrade.
7.2. It is permissible to transport the lens in its packing case by any mode of transport except sea.
Air transport should be done in hermetically sealed heated compartments.

Figures
Figure 1
Figure 2