"Description of a German rangefinder sight with night vision
The device is designed to measure distance and to observe at night. Observation at night is performed by attaching special lenses to the rangefinder.
The lens consists of a cylinder that holds a light sensitive plate, a diaphragm, and a lamp for illumination. It weighs about 250 grams. The lamp is powered by six dry cells.
The light sensitive plate is held between two pieces of glass. It is flourescent.
Before observation, the plate is illuminated. During the summer the lamp is held further away. Special lights exist for winter and summer illumination. at a temperature of 10 degrees the illumination time is 5 minutes.
The prisoner did not know the chemical composition or method of production of the light sensitive plates.
Observation cannot be performed in colour. The output is in grayscale.
During the day the rangefinder can work without the lens, which is held in a lightproof container. Observation is not possible during complete darkness or fog. A man is visible from 3 km away during a full moon. If the light is insufficient, the clarity of the image decreases and the visible range decreases as well.
Based on interrogation of POW observation officer from the 8th Artillery Regiment Lieutenant Hager.
Approved: Chief of Intelligence, Artillery HQ of the 53rd Army, Captain Roshupkin
Approved: Assistant Chief of Intelligence, 5th Guards Division, Guards Captain Kozlov
January 22nd, 1945"