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.
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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.
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The FED is of the same quality as the Industar-22 and Industar-50, and it was made exclusively by the FED factory in Kharkov.
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Evoltution steps:
- 1-turn focus (around 315 degrees)
- 1/2-turn focus in 1935
- new serial number system
- coated glass
- new aperature settings 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
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Technical Characteristics (1-turn version):
Aperture settings: 3.5 to 18
Glass: Uncoated
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Technical Characteristics (prewar 1/2-turn version):
Aperture settings: 3.5 to 18
Glass: Uncoated
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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
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