Focal Length: 18-50mm Aperture Range: F2.8- F22 Lens Construction:10 groups, 13 elements (1 SLD and 3 aspherical lenses Angle of View (APS-C):76.5° (W) -31.7° (T) Diaphragm Blades:7 (rounded diaphragm) Minimum focusing distance::4.8 (W) -11.9 (T) in. Maximum magnification ratio: 1:2.8 (W) -1:5(T) Working distance of just over an inch (2.7cm) from the front element at 18mm Versatile focal range and excellent optical performance Stepping motor provides swift, accurate, and quiet autofocus High-precision, durable brass bayonet mount with dust and splash-resistant structure