The EF 800mm f/5.6L IS USM Lens from Canon is currently Canon's longest telephoto lens, and an excellent choice for any long-distance application such as outdoor sports, wildlife, and photojournalism. Even though it has a long 800mm focal length, the magnesium alloy used in the construction for this lens makes it lighter then the 600mm f/4L lens, weighing in at less than 10 lb.
This lens shares the same lightweight, weather-resistant construction as the rest of the L-series super telephoto lenses, as well as their improved control layout, weight distribution, and mechanical manual focus. Its two-mode Image Stabilizer system allows the use of shutter speeds up to four times slower with no perceptible increase in image blur. Mode 1 is best used for still subjects while Mode 2 is optimized to pan with moving subjects.
An ultrasonic autofocus motor enables fast, smooth and quiet AF action, while a focus preset function allows you to store focusing positions and return to them in an instant when needed. An AF stop button will pause autofocus with just a touch and manual focus override allows precise manual focus even in AF mode. A focus range limiter function lets you to save time by establishing a focus distance range for your specific subject.
For optimum visual performance, the lens incorporates four types of special optical elements: aspherical elements to correct spherical aberrations, and refracting Fluorite, UD and Super UD (ultra-low dispersion) elements to eliminate secondary chromatic aberrations. An integrated, rotating tripod collar provides balance and stability and the rear drop-in filter slot and holder enable easy filter use. A large lens hood, hard case and lens caps are included.