Canon RF Mount. The Canon RF 800mm f/5.6L IS USM belongs to Canon’s line of RF-mount lenses. It’s compatible with RF-mount cameras, but it doesn’t work with Canon EF-mount cameras.

Versatile Super-Telephoto Prime. This lens’s super-telephoto length makes it great for sports, nature, journalism, and wildlife photography, and its reasonably light weight means you can use it on a monopod or even hand-held in short bursts. The f/5.6 aperture isn’t great for low-light shooting, so you’ll probably want to stick with outdoor lighting conditions for best results. Its rounded nine-blade diaphragm gives you great depth-of-field control for selective focusing.

Optical Image Stabilization. The built-in optical image stabilization system provides up to 4.5 stops of correction, allowing you to shoot in lower light and at lower shutter speeds without worry. There are three stabilization modes, each of which suits a different purpose: a standard single-shot mode, a panning-optimized mode, and a mode that only activates the stabilizer during the exposure.

Ultrasonic Focusing Motor. This lens uses a ring-type Ultrasonic Motor to provide fast, accurate, and nearly silent autofocus performance for both still and video shooters. You also get full-time manual-focus controlled by a customizable electronic focusing ring with three sensitivity levels, and a Focus Preset button that can quickly recall two programmed focus positions.

Advanced Optical Design. This lens’s 18-group/26-element optical design includes 1 Ultra-Low Dispersion element, 1 Super UD element, and 2 fluorite elements which combine to reduce aberrations, color fringing, and distortion for maximum clarity, color accuracy, sharpness, and rendering. Canon has applied Super Spectra and Air Sphere coatings to the lens elements to further combat ghosting and flaring, even in harsh lighting.

Teleconverter Compatible. The RF 800mm is compatible with the Extender RF 1.4x and Extender RF 2x teleconverters, both of which are available as separate rental items. You can use these teleconverters to extend the lens’s focal length to 1120mm and 1600mm, respectively.