The EF 400mm f/4 DO IS II USM lens delivers brilliant high-speed performance for professionals with minimal glare and superb image quality. Taking advantage of the best in lens technology, it features gapless dual-layer diffractive optical elements for improved diffraction efficiency with reduced flare. These elements are arranged with a large-diameter ground aspheric lens and a UD lens for a new level of sharpness and clarity. New coatings help to reduce ghosting, ensure excellent color balance and reduce fingerprints on the front and rear of the lens. Professional L-series dust- and water-resistant construction is complemented by impressive performance: a 3 mode Image Stabilization system offers up to four stops of compensation and can even prevent operational errors when the camera is mounted on a tripod. AF stop buttons placed on the front of the lens can automatically stop focusing at any time; full time manual focus ensures complete control no matter the AF mode, and a Power Focus (PF) mode makes for smooth focus transitions when shooting movies. The EF 400mm f/4 DO IS II USM focuses down to 10.8 ft. (3.3 meters), has a 9-blade aperture for pleasing, soft, out-of-focus areas, and is constructed with environmentally friendly lead-free glass.