This new super wide-angle zoom lens, designed for exclusive use with digital SLR cameras using a sensor smaller than full frame, provides the extended focal length covering 17mm (when converted to 35mm format) that is desired by today's advanced and pro photographers using digital SLRs. The lens features an entirely new optical system designed for optimal performance with digital SLR cameras. Di II lenses are designed for exclusive use on digital cameras with smaller-size imagers and inherit all of the benefits of our Di products. These lenses are not designed for 35mm film cameras and digital cameras with image sensors larger than 24mm x 16mm.