Covering a versatile wide-angle range, 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. Benefitting the flexible zoom range is a sophisticated optical design, which includes one Super-UD element and three aspherical elements to control chromatic and spherical aberrations, and a Super Spectra coating has been applied to limit flare and ghosting for improved contrast. 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.