The Carl Zeiss Jena Flektogon 20mm f4 wide-angle is a truly desirable lens, the 20mm 4 Flektogon is famed for its lack of distortion and also a remarkable broad light and shadows reproduction. Architecture, urban and landscape photographers love this lens because lines turn out totally straight. The lack of distortion in this lens is memorable – hats off to the engineers at Carl Zeiss Jena for pulling that off. You will not spend time in post production to straighten lines. Contrast is very good and and this lens shows absolutely faithful colors. Despite originally this Flektogon come in an Exakta mount, its easilly adapted to any new digital SLR or Rangefinder cameras as Nikon, Canon, Pentax, Olympus, Sony. Actually I used for some months attached to my Sony A7RIII, I'm also including this e-mount adapter plus a metal super wide-angle lenshood with the lens. The last two photos were taken with this lans in a Sony A7RIII camera. Weight: 0,320Kg or 0,480Kg with Sony adapter. Shipping to all European Union countries: EUR25,00 (insured) and for Great Britain: EUR40,00 Technical specs: Optical elements: 10 in 6 groups Angle of view: 93° (35mm full frame) Aperture: 4 – 22 Mount: Exacta Made in East Germany Aperture blades: 6 Filter diameter: 77mm Minimum focusing distance: 16 cm