The Canon EF 11-24mm f/4L USM Lens is a member of the esteemed L-series of lenses designed for full-frame EOS DSLRs. It's Wide-angle zoom 11-24mm f/4 lens is compatible with full-frame, as well as APS-C-sized models where it will provide a 17.6-38.4mm equivalent focal length range. Both SWC and ASC coatings have been applied to the elements in order to reduce lens flare and ghosting for increased contrast and color accuracy. As a member of the esteemed L-series, this lens is sealed against dust and moisture for working in inclement environmental conditions. This lens covers ultra-wide to wide-angle perspectives and backs up its versatile zoom range with sophisticated optical components and intuitive handling. In regard to focusing performance, a ring-type Ultrasonic Motor offers fast, smooth, and near-silent autofocus, which is further benefitted by full-time manual focus operation and an internal focusing design.