This lens uses the EF-S mount which is only compatible with Canon Digital Rebel, Digital Rebel XT, 20D, and 30D cameras. This exciting new zoom lens provides ultra wide-angle coverage to the EOS 20D and Digital Rebel shooter. Equivalent to a 16-35mm zoom, it offers excellent performance and optics designed from the ground-up for digital SLR use. Three Aspherical lens elements, plus a Super-UD element, assure image quality. Its ring-type USM means fast and silent AF along with full-time manual focus. It focuses as close as 9.5 inches.