This Canon EF 17-40mm F/4.0 L USM lens can be mounted on SLRs as well as on digital bodies. With a 17 mm - 40 mm focal length, the L-series wide-angle lens can be used for landscape photography. It features auto (using USM) and manual focus, an has a maximal apparture of f/4.0. Futhermore, it can fit different filters of 77mm diameter.