FED 1:2 F=50mm is normal prime lens for 35mm rangefinder cameras FED-NKVD, called FED-C, or "commander".
Operating segment - non-standard (compared with a standardized, after the war for the rangefinder = 28.8mm), about 28.4-28.6 mm. Because of this infinity is not where it should be.
Aperture range 2-18.
Links to online resources:
Posted by: SharkDD Date of publication: 27.04.2016