'Industar' brand lenses use a very simple but effective optical design of 4 lenses in 3 groups, similar to the 'Tessar' design.

I-22U 1:3.5 F=50mm P has only an aperture control ring; the ring rotates smoothly, without fixed values. The diaphragm consists of 10 blades and closes to F/16. The lens does not have a focusing ring and is therefore not suitable for conventional types of shooting, but it can be used perfectly for simple macro photography.

I used I-22U 1:3.5 F=50mm P on Nikon cameras using 2 adapters: M39-M42 and M42-Nikon F, you can get by with one M39-Nikon F adapter. On Nikon cameras the lens is always focused at a distance of 20 cm from the focal plane, and to focus you have to move the camera itself.

Use with modern cameras

Lenses with an M39 mounting thread (for enlargers, M39 X 1/28.8), such as the lens from this review, are very easy to use on modern cameras; all you need to do is choose the right adapter. On SLR cameras, the lens can only work in macro mode (shoot small objects from a short focusing distance). It will be possible to achieve infinity focusing on mirrorless cameras. The cheapest adapters can be found on third-party sites.

For use on modern Canon EOS digital SLR cameras, you need an M39-Canon EOS adapter. Also, the M39-Canon EOS adapter can be easily replaced with two adapters: M42-Canon EOS + M39-M42. In any case, the lens will always be focused at close distances.

For use on Nikon SLR cameras, you need an M39-Nikon F adapter. Also, one M39-Nikon F adapter can be easily replaced with two adapters: M42-Nikon F + M39-M42. In any case, the lens will always be focused at close range.