The use of a multi-group zoom system delivers a lightweight and compact zoom lens that achieves high picture quality over all focal lengths. Covering a broad range from a wide-angle 28mm to a medium telephoto 105mm, the lens delivers a closest focusing distance of 0.5m. The autofocus employs a ring-type USM and inner focusing system, so it is as quiet as it is quick. It also has a full-time manual focusing mechanism that allows small changes to be made to the focus very quickly, without leaving autofocus mode. The wide zoom ring and non-rotating front lens element offer outstanding operability.