Lets review wide angle objective lens KMZ Mir-20, it was produced by KMZ plant from 1973 year to 1992 year and by other plants, now it can be bought through private ads in conditions from “new” to “with marks of use”. It has 20 mm fixed focus and field of view 96 degrees; 1/3.5 – 1/16 diaphragm; 24 × 36 mm frame size; and minimal focusing distance 0.18 m. Objective lens has 9 lens elements in 8 groups with enlightened optics or with protective and anti-reflective multi-coating, depending on objective lens modification. KMZ Mir-20 is attached to camera via M42×1 mount, using different adapters and converters it can be attached to cameras with different mounts standards. It has no automatic focusing and diaphragm control, so they should be set manually with use of control rings. Because of this it most suitable for experienced photographers, who know which settings to use in different situations. Optical filters can be attached to objective lens from back side with use of M28×0.75 mount. All in all it is very good objective lens, accounting its low lens elements amount and their high quality ( in USSR and in Russia optics production takes its roots in military area and quality of production is very high ), it is far more superior, than zoom objective lenses with similar characteristics; and taking into account its low price ( especially when it is bought through private ads ) it is very competitive with other fixed focus wide angle lenses.
