Canon EF-S 17-55mm f/2.8 IS USM Lens Ultimate

Canon EF-S 17-55mm f/2.8 IS USM Lens A tremendously flexible standard zoom for APS-C-format DSLRs, the Canon EF-S 17-55mm f/2.8 IS USM Lens pairs the 27.2-88mm equivalent focal length range with a bright f/2.8 constant maximum aperture. Benefitting this design is a sophisticated optical layout, which includes both Ultra-Low Dispersion glass and aspherical elements to significantly reduce chromatic and spherical aberrations for improved clarity and sharpness throughout the zoom range. A Super Spectra coating has also been applied to individual elements to suppress flare and ghosting for increased contrast when working in bright environments. Beyond the optical attributes, this 17-55mm is also characterized by its advanced three stop-effective Image Stabilizer system to minimize the appearance of camera shake. Also complementing handling is a sophisticated ring-type USM, which provides quick, quiet, and accurate autofocus performance along with full-time manual focus override. Versatile wide-angle to portrait-length zoom is designed for APS-C-format Canon EF-S-mount DSLRs and offers a 27.2-88mm equivalent focal length range. Bright constant f/2.8 maximum aperture affords consistent illumination throughout the zoom range and also affords greater control over depth of field for working with selective focus techniques. Two Ultra-Low Dispersion glass elements noticeably reduce color fringing and chromatic aberrations for high clarity and color fidelity. Three aspherical elements minimize spherical aberrations and distortions for improved sharpness and accurate rendering. 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. An Optical Image Stabilizer helps to minimize the appearance of camera shake by up to three shutter speed stops to better enable working in low-light conditions and with slower shutter speeds. A ring-type Ultrasonic Motor (USM), along with an internal focusing design and optimized focusing algorithms, is employed to deliver fast, precise, and quiet autofocus performance as well as full-time manual focus override. Rounded seven-blade diaphragm contributes to a pleasing out of focus quality that benefits the use of shallow depth of field and selective focus techniques.