Lets review extra-wide angle objective lens ( “fish eye” ) Zenitar 2,8/16, that is produced in Russia. It was developed and now is manufactured by «Krasnogorskiy Plant of S.A. Zverev» for following bayonets : M42×1, Nikon, Pentax and Canon, it also can be used with other mounts via adapters and converters. It has 180 degrees field of view, 16 mm focal length, maximal and minimal apertures : f/2,8 – f/22 ( with 6 diaphragm blades ), frame size : 24 × 36 mm, and minimal focusing distance is 0.3 m. To obtain optimal results, there is need to use full-frame cameras, otherwise field of view will be cut near the edges. It has 11 lens elements in 7 groups, all of them are coated with multilayer protective and anti-reflective coating. Objective lens does not have automatic focusing and image stabilization; they would not work any way with adapters and converters; so, this lens is appropriate for experienced photographers, which know which settings to use for different scenes. It has great picture quality at the center and strong geometrical distortions at the edges ( they are inherent for all objective lens of this type ). Zenitar 2,8/16 has fixed focus and small amount of lens elements, so by image clarity, sharpness and lightness it is far more superior, than standard zoom objective lens of cameras. Wherein it has much smaller price, than other competing extra-wide angle objective lens.
