Industar's 50-2 50mm f/3.5 — a compact Soviet Tessar-type M42 pancake standard prime.
The Industar-50-2 50mm f/3.5 is a Soviet standard prime of the Tessar type, a compact pancake-style normal lens made in M42 mount from the early 1960s. It was a common budget standard on Soviet SLRs and remains popular for its small size and simple, sharp rendering.
This is a manual-focus M42 screw-mount lens with a 50mm focal length and a maximum aperture of f/3.5, built on the four-element Tessar formula. Focus and aperture are set by hand on the barrel. It is a very slim all-metal pancake lens. Precise weight and filter figures are not asserted here beyond the verified focal length and aperture.
The 50mm standard view suits street, travel and general shooting, and the slow f/3.5 aperture with the Tessar design gives sharp, contrasty results when stopped down a little. Its main appeal is its tiny pancake form, making it one of the most portable M42 standards and a neat everyday lens on compact bodies.
Used copies are very cheap and plentiful. Inspect for haze, fungus and cleaning marks, confirm the aperture blades are dry and the ring works, and check focus feel, which can be stiff on some copies. The small size makes it a favourite pancake on mirrorless via an M42 adapter, keeping a slim overall package.