Sigma 20mm f/1.8 EX DG - Sony A Fit

The SIGMA 20mm Sony Lens Fit is the first super wide-angle lens in the world with a large aperture of F1.8 and angle of view of 94.5 degrees; Its macro focusing capability has a minimum focusing distance of 20cm/ 7.9 inches; The iris diaphragm has 9 diaphragm blades to obtain beautiful out-of-focus images; The incorporation of the aspherical lens element in the front as well as rear lens group, minimises distortion, spherical abberation and astigmatism; In addition the lens has a non-vignetting optical construction, in order to obtain adequate peripheral brightness with open aperture which is especially desirable for digital cameras; Additional features include the rear focus system that eliminates front lens rotation which then allows the use of a Perfect Hood and easy use polarising filters; The lens is easy to hold, since the focusing ring does not rotate during auto-focus, yet it provides adequate focusing torque during manual focusing of the lens; The materials used for the lens are lead and arsenic free ecological glass.