Weighing just 2,895g, this is the lightest 400mm f/2.8 full-frame lens in its class, using three fluorite elements and a magnesium alloy build to achieve that portability without sacrificing durability. Its XD Linear Motors deliver fast, accurate autofocus, while the 11-blade aperture and Nano AR Coating produce sharp images with smooth bokeh and minimal flare. This lens is best for sports and wildlife photographers who need to pan quickly and shoot handheld in low-light conditions.