The FED 50mm lens design is a Leitz Tessar formula.
4 elements in 3 groups. Elements 3 and 4 are cemented.
The diaphragm is between element 2 and 3.
.
This lens appeared first on the first FED in 1934 and was also known as Industar-10.
In the late 1940's this design was handed over to KMZ and the Industar-22 was born.
.
The FED 50/3.5 design and appearance stayed virtually unchanged for decades, but the optical parameters were constantly improving. Restitution increased, coating appeared in 1949/1950. By the mid 1950's the lens was "finalized", and the later versions of the lens are sharp and contrasty, well suited for black and white and color photography.
The FED evolutions are of the same quality as the Industar-22 and Industar-50, and it was made exclusively by the FED factory in Kharkov.
.
Evolution steps:
- 1-turn focus (around 315 degrees)
- 1/2-turn focus in 1935
- new serial number system
- coated glass
- new aperture markings till 16 instead of 18, named 50MM instead of 50M/M
- 8 blades instead of 10
- new serial number system, serial number on the front side with focus markings
- lost button on the focus lever
.
Technical Characteristics (1-turn version):
Aperture markings: from 3.5 to 18
Glass: Uncoated
.
Technical Characteristics (prewar 1/2-turn version):
Aperture markings: from 3.5 to 18
Glass: Uncoated
.
Technical Characteristics (postwar version):
Focal length: 52mm
Angle of Coverage (35mm film): 45°
Focusing: 1m till Infinity
Aperture markings: from 3.5 to 16
Glass: since 1949/1950 Coated
Optical registration (back focus): 28.8 ±0.02mm
Mount: M39x1mm, the lens mounts and RF couples with any Leica or Leica copy (FED, Zorki etc.)
Filter size: 36mm slip-on type
Finish: Polished chrome, Matte chrome
_______________________________________________________________________________
