Mir's 1 37mm f/2.8 — a Flektogon-derived Soviet M42 wide-angle prime.
The Mir-1 37mm f/2.8 is a Soviet wide-angle prime, a design based on the Zeiss Flektogon retrofocus formula that won a Grand Prix at the 1958 Brussels World's Fair. Produced from the late 1950s in M42 mount, it was a well-regarded wide-angle of the Soviet lens range.
This is a manual-focus M42 screw-mount lens with a 37mm focal length and a maximum aperture of f/2.8. Focus and aperture are set by hand on the barrel, and it is a compact all-metal wide-angle of retrofocus design. Exact element and filter figures are not asserted here beyond the verified focal length and aperture, in line with the accuracy standard.
At 37mm the lens gives a mild wide-angle view close to a natural perspective, useful for street, travel, landscapes and interiors. Based on the respected Flektogon formula it renders with good sharpness stopped down and pleasant character, and is regarded as one of the better Soviet wide-angles for general use.
Used copies are affordable and fairly common, with quality varying between production runs. Inspect for haze, fungus and cleaning marks, confirm the aperture blades are clean and the ring works, and check focus. Verify the mount is M42. An M42 adapter allows use on mirrorless cameras for a characterful mild wide-angle.