Characterized by a revamped optical design, the EF 16-35mm f/2.8L III USM from Canon is a workhorse wide-angle zoom and member of the well-regarded L-series of lenses. Featuring a series of specialize espandi...d elements, this lens utilizes a trio of aspherical elements and two ultra-low dispersion glass elements to control a variety of aberrations for high sharpness and clarity.