Distagon T* 2,8/21 ZE pre Canon recenzia 

Reach a new horizon in focal length
This legendary super wide angle lens will set new standards in its focal length class. Exceptional color control allows for extraordinary high contrast pictures without any color fringes. Thanks to the Carl Zeiss T * anti reflection coating and its outstanding attenuation of stray light, the Distagon T * 2,8 / 21 provides brilliant results under all lighting conditions. With a close focusing of only 0.22 m (0.72 ft) it is as attractive for landscape photography as for subjects with dramatic perspectives. The Distagon T * 2,8 / 21 with F bayonet (ZF), EF bayonet (ZE) and K bayonet (ZK) is suitable for analog or digital full-frame SLR cameras. The large front fi lter diameter even allows for the use of standard screw-in fi lters when combined with the standard lens shade.
Technical specifications
Focal Length     21 mm
Aperture range     f/2.8 – f/22 (1/2 steps)
Focusing range     0.22 m – infinity
Number of elements/groups     16/13
Angular field (diag./horiz./vert.)     90 /81 /59 °
Filter-Mount     M 82 x 0.75
Weight     720 g
Diameter     87 mm
Dimensions (with caps)     112 mm