The Zoom Lens EF24-70mm f/2.8L USM was developed as the successor to the EF28-70mm f/2.8L USM lens released in November 1993. Featuring a new optical system design, the new zoom lens delivers an expanded zoom range with a 24 mm wide-angle focal length, ideally suiting it to digital image sizes, while also maintaining or improving on the outstanding image quality of the superseded model.Moreover, the power of the focusing lens group has been increased to allow a minimum focusing distance of just 0.38 meters, the shortest in its class at the time, throughout the entire zoom range. The new EF24-70mm f/2.8L USM also features a circular diaphragm, to give better background blur, and utilizes only lead-free glass optics in consideration of the environment. more info