This 28mm optical bijou with a 76° angle-of-view, is the FED 4,5/28mm rangefinder-coupled, wide-angle lens for Leica mount—the first fast 28mm lens.
Originally released in 1938, the FED 4,5/28mm lens body closely resembles Leitz Elmar 35mm f/3,5 on the outside but its axially-symmetrical optical formula—6 air-spaced lens elements in 4 groups—is superior to Leitz Hektor 6,3/28mm or Zeiss Jena Tessar 8/28mm or any other 28mm lens for 35mm format cameras of the time.
The miniature dimensions of the entire optical block is impressive achievement for a fast 28mm wide-angle lens from 1938. The diameter of the optical block is ~ 7mm for the outer elements and ~ 6mm for the inner elements, while the thickness of the third optical element (back-to-front) does not exceed the 6-7 tenths of a millimeter. Imagine the required skills for grinding and assembling these optical elements—entirely by hand—while maintaining tight tolerances, in 1938!
Specs: 6 lens elements in 4 groups—cemented outer pairs. 6–blade aperture, classic ƒ4,5 to ƒ18 scale.
Produced at the Kharkov's FED factory between 1938 and 1939 in very small batch. The external viewfinder was produced only in 1939 and it's rarer than the lens.
Photo credit: © WestLicht Photographica Auction