The EF-S 10-22mm f/3.5-4.5 USM is designed for Canon EF-S-mount APS-C DSLRs, and provides a 16-35.2mm equivalent focal length range to suit working in a wide array of shooting conditions. Additionally, this lens sports a ring-type USM for quick and quiet autofocus performance and full-time manual focus override, and an internal focus design also quickens focusing speeds and maintains the overall lens length during operation. One Super-Ultra-Low Dispersion glass element noticeably reduces color fringing and chromatic aberrations for high clarity and color fidelity. Super Spectra coating has been applied to individual elements to minimize ghosting and flare for greater contrast and color neutrality when working in strong lighting conditions. Rounded six-blade diaphragm contributes to a pleasing out of focus quality that benefits the use of shallow depth of field and selective focus techniques.