Ultra-wide-angle MIR-20M 20mm f/3.5 fast. Carl Zeiss Flektogon copy. Mir-20 20mm f/3.5 is an interchangeable ultra-wide-angle fast lens. The basis of the optical scheme of the Mir-20 lens was borrowed from the Carl Zeiss Jena Flektogon 20 mm f/2.8 lens. Some changes have been made to the scheme. The lens produces a sharp image, especially in the central region, already from aperture 3.5, from aperture 5.6 it is very sharp. The drop in resolution at the edges of the frame is quite noticeable. The Mir-20 20mm f/3.5 has almost no geometrical distortions. Color reproduction is bright and saturated. Slightly shifted to the area of?? warm tones. The Mir-20 lens is perfect for shooting landscapes, interiors, architecture, genre and reportage. Fits well on modern digital SLR cameras. When set to hyperfocal distance, you can forget about autofocus and shoot very quickly. Mir-20 20mm f/3.5 lens features. 96° diagonal field of view. Resolution (0/10/20mm)1: 50/35/30 lines/mm. Specification resolution (center/edge): 50/20 lines/mm. Light transmission coefficient: Mir-20M – 0.75; MC Mir-20M – 0.90. Color formula: Mir-20M – 11-0-2; MC Mir-20M — 11-0-0. Lens length with caps: Mir-20M – 68 mm. The largest frame diameter: Mir-20M – 92 mm. Format: 35mm mirror SLR/DSLR. Type: Fixed focal length (fixed). System: M42, Nikon F (FX, DX), Pentax K. Optical design: 9 elements in 8 groups.