Covering a versatile wide-angle range, the Canon EF-S 10-22mm f/3. 5-4. 5 USM is designed for 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.
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