Canon EF 16-35mm f/2.8L USM Ultra Wide Angle Zoom Lens for Canon… The first EF wide-angle zoom to combine three Aspherical elements and Canons UD glass, the lens remains compact while providing superior image quality across its range. Constructed to pro standards, its also highly resistant to dust and moisture. A superb lens that covers nearly every professional wide-angle task. Outstanding optical performance comes from three Aspherical lens elements, and (for the first time ever in an EF wide- angle zoom lens) two Ultra-low Dispersion UD elements. Weather resistant construction, a rear gel filter holder, close-focusing to 11 inches (0.28m), and a circular diaphragm are among its many highlights. Micro UltraSonic Motor (USM). F/2.8 constant maximum aperture. Super Ultra-low Dispersion glass; inner focusing; aspherical lens; full-time manual focus. EF mount; ultra-wide zoom lens. Focal Length Description: 16-35 millimeters. Lens Type: Wide Angle. Compatible Mountings: Canon EF. Camera Lens Description: 12. Product Dimensions: 4.06 x 3.31 x 3.31 inches. Item Weight: 1.32 pounds. Item model number: 7261A002.