This lens replaced its predecessor Industar-26m as a standard lens on the FED-3 and early FED-4 cameras. The optical design of the Industar-26m was improved and aperture stop-clicks were introduced.
This is one of the newer multicoated LTM lens made by the Soviet (now Ukrainian) photo industry. It is sharp and contarsty, with smooth focusing action and the aperture click-stops. The lens later evolved in all-black Industar-61LD.
The lens was also made in universal 42mm mount for Zenit cameras, named Industar-61L/Z.
Focal length: 53 mm
Aperture: 1:2.8 (from 2.8 to 16), Click-stop settings.
Field of coverage: 45°
Focusing: 1 m - Infinity
Filter size: M40.5x0.5 mm
Optical registration (back focus): 28.8± 0.02 mm
Mount: M39x1 mm (LTM). The lens mounts and RF couples with any Leica or Leica copy (FED, Zorki etc.)
The glass is coated; the barrel has chrome finish with black enamel rings.
(Source: www.fedka.com)