As a wide-angle lens, it shows its superior efficiency when it is used for picture taking at full-aperture openings. Special emphasis is put into it so that it can be also used as a standard lens. It incorporates the full range of the aberration-free system to assure high resolving power at a photographic distance of 30cm. Equipped with a coupling pin to the CAT System. SPECIFICATIONS Type: Super wide-angle Angle of view: 63 degrees Minimum Aperture: F/22 Closest Focusing Distance: 1ft Filter size: 55mm Lenshood: optional BW-55A Length: 2 3/8 in Weight: 12 oz.