The third generation ultra-wide angle Canon EF 16-35mm f/2.8L III USM lens features a fixed f/2.8 maximum aperture for outstanding image quality and impressive low-light performance across the range. This professional favorite lens features a constant f/2.8 max aperture, edge-to-edge clarity, significantly improved image distortion, and reduces chromatic aberration. It offers premium image quality from an ultra-wide-angle zoom lens, versatile wide-angle focal lengths, fast constant aperture, durable L-series construction, and advanced autofocus. Optical Features/Specifications: Image size - 35mm film equivalent focal length (mm) - Angle of view (horzntl, vertl, diagnl) 98 - 54 degrees.