This unit was made in the late 1950's (this is my best guess). It was used on military aircraft for training purposes. The camera is powered by 27 VDC.

The camera is equipped with a fixed focus 100 mm f:6.3 lens. There are three aperture settings corresponding to the weather conditions: CLEAR, CLOUDY, OVERCAST. The S-13 has a hinged door which can be easily opened without removing the unit from the aircraft. You only need to unzip the protective canvas cover and release a side lock.

The cassette is the only removable part of the S-13. The cassette holds 5.2 m of special aerial b/w 35 mm film. This was a fast (around 1000 ASA) film called A1000. The cassette has a permanently attached label for recording the following data: Name, Excercise number and the date.
(Source: Yuri Boguslavsky, Fedka.com)

In pictures 12 & 13 you see a camera pod for C-13 camera. this pod is for Su-15, Mig-21 and Mig-23 aircrafts.

Picture 14 shows a KOMZ made S-13 with an FS-2 f/4.5 300mm lens attached.