Diffractive Optics. Gapless dual-layer diffractive optics allow the lens to be smaller and lighter compared to traditional Canon super telephoto lenses. This advanced optic system reduces chromatic and spherical aberrations, ensuring high quality images.

Super Telephoto Focal Length. The 400mm focal length is popular for sports and wildlife photographers, with this lens targeting the latter with its reduced size and weight.

Image Stabilization. The in-lens stabilizer provides up to 4 stops of correction to combat image shake. There are three IS modes to choose from (Standard, Panning, and During Exposure Only), and automatic tripod detection means you don’t have to turn it off when locked down on a tripod.

Ultrasonic AF Motor. The ultrasonic motor provides fast, silent autofocus performance. It has full-time manual focus override, a focus limit switch and stop buttons for preventing focus hunting, and a Power Focus Mode for pseudo-follow focus movements.

Build and Optics. Its weather-resistant build lets you keep shooting when the weather gets questionable, with a fluorine coating to keep the front and rear elements free of water and smudges. Besides the diffractive optics system, the 400mm f/4 DO IS II also features one large-diameter ground aspherical element and one Ultra Low Dispersion element to improve overall image quality. The integrated tripod foot allows easy attachment to a tripod or monopod, and the included drop-in UV filter takes care of ultraviolet light.