It is a copy of the Leitz Elmar lens for the Leica II camera. It was produced as a regular for early Zork.
Specifications:
Focal length: 50mm
Field of view angle: 46°
Frame size: 24×36 mm
Number of lenses/groups: 4/3
Working length — 28.8 mm
Relative opening: 1:3.5
Aperture scale limits: 1:3.5–1:16
Number of diaphragm lobes — 10
Aperture adjustment — stepless
Aperture preset — missing
The near focus limit is 1 m
Connections:
lens with camera — M39×1
for screw—in attachments - no
for put-on attachments — ∅27 mm
Mounting location for light filters: no
Resolution according to TU (center/edge): 32/22 lines/mm
Light transmission coefficient: 0.80
Weight — 106 g
The lenses of the lens have a single-layer illumination, as evidenced by the red letter P on the front end. Enlightenment of a bluish-purple hue.
The design provides that during inactivity the lens is sunk inside the camera, thereby reducing the dimensions of the camera in the case.
To bring the camera into working condition, the lens must be pulled out of the camera by the front ring with a notch and turned clockwise by the same ring, thereby fixing it in the working position.
You need to focus by moving a special leash.