This lens replaced its predecessor Industar-26m as a standard lens on the FED-3 and all later FED cameras. The optical design was improved, and a new, Lanthanum glass was used (letter L is for Lanthanum, D is for Dal'nomer - Rangefinder.
This is the newest 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.
It is still in production by FED factory in Kharkov, Ukraine. The lens was also made in universal 42mm mount for Zenit cameras, its name was 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 black enamel finish.
(Source: www.fedka.com)
Known serial numbers:
#lens ______ #cam/type _____ mm _ blades _ name ____________ owner/source