Canon RF Mount. The Canon RF 100-300mm f/2.8 L 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.

Fast, Versatile Telephoto Zoom. This lens’s versatile telephoto zoom range makes it perfect for portrait, fashion, indoor-sports, theater, and video applications. Its fast f/2.8 constant aperture and circular nine-blade diaphragm give you extensive depth-of-field control, let you work in available light, and help produce smooth, pleasing bokeh while keeping your subject sharp.

Advanced Optical Design. This lens’s 18-group/23-element optical formula includes 1 fluorite element, 1 aspherical element, and 4 Ultra-Low Dispersion elements to combat chromatic aberrations and color fringing throughout the zoom range while maximizing clarity, color fidelity, and sharpness. Canon has applied Air Sphere and Super Spectra coatings to each lens element to further minimize ghosting and flare, even in harsh light.

Fast, Ultra-Precise Autofocus. The Dual Nano Ultrasonic Motor (USM) autofocus system uses a combination of ring-type USM and stepping-motor (STM) mechanisms to provide fast, accurate, and nearly silent autofocus performance for both still and video shooters. There are two separate, independently actuated focusing groups to give you even greater sustained sharpness throughout the zoom range, and you get an AF/MF switch for full-time manual-focus override. You can set the focus-range limiter to the full focusing range, from 5.9 feet to infinity, or from 19.7 feet to infinity for faster performance if you’re only working with distant subjects.

Additional Focusing Features. This lens’s internal focusing and zooming design means it maintains its overall length throughout the zoom and focus ranges, which makes for faster operation. A Focus Preset button allows for pre-focusing on a particular spot, storing its focus distance, and then instantly returning to that position. Four programmable L-Fn buttons let you control a host of lens and camera functions.

Optical Image Stabilization. The 100-300mm f/2.8 L’s built-in image stabilizer compensates for 5.5 stops of camera shake so that you can shoot hand-held, in lower light, and at slower shutter speeds without worry. When you pair this lens with newer EOS R bodies that themselves feature five-axis in-body image stabilization, you get up to 6 stops of shake correction.

L-Series Design. A customizable control ring lets you adjust a range of exposure settings, including aperture, ISO, flash control, white balance, and more. A built-in rotating tripod mount lets you use this lens on a tripod or monopod, and lets you quickly switch between portrait and landscape shooting orientations. A weather-sealed build keeps you shooting in inclement conditions, and a fluorine coating on the front lens element protects against moisture, fingerprints, and debris.

Extender Compatibility. The 100-300mm is compatible with the Canon RF Extender 1.4x and 2x, each of which will extend the lens’s effective reach.