The Canon RF 100-300mm f/2.8 L IS USM is a well-rounded lens for indoor sports, events and theater, fashion, and other subjects benefitted by the unique mixture of long reach, high speed, adept image stabilization, and fast autofocus.  This RF 100-300mm f/2.8 maintains the quality and speed 300mm f/2.8 shooters are looking for while adding the versatility of a zoom that widens up to 100mm. Building on the legacy of the popular EF 300mm f/2.8 prime lenses, the 100-300mm zoom design offers more versatility for tracking moving subjects, recording candid moments from a distance, and backing off from scenes a bit for a wider frame for more context. Despite switching to a zoom design, this lens retains the a bright and constant f/2.8 maximum aperture that excels in available lighting conditions and helps to achieve a shallow depth of field to isolate subjects against a blurred background. As a lens designed for sports, events, and other moving subjects, AF and IS functions have been optimized for quick and precise performance along with the ability to work with the lens handheld or from a monopod if desired. Its Dual Nano USM system uses both a ring type USM and an STM mechanism to realize quick and accurate focusing. Two separate focusing groups are independently actuated for greater maintained sharpness throughout the zoom range and at different focus positions. Focus range limiter can be set to the full focusing range, from 5.9' to infinity, or from a 19.7' to infinity range for quicker performance if working exclusively with distant subjects. Optical image stabilization compensates for up to 5.5 stops of camera shake; if paired with an EOS R camera featuring in-body image stabilization, this lens also supports Coordinated IS that offers up to 6 stops of shake correction. 

 This RF 100-300mm f/2.8 zoom features the durability, weather sealing, and intuitive design professionals expect from an L Series lens. For intuitive handling and focus control, there is a Focus Preset button near the rear of the lens, which can be triggered with your right hand during use. This function allows pre-focusing on a spot, storing this focus distance, and being able to instantly return to the memorized position at the push of this button. Alternatively, a side switch enables utilizing this buttons as an secondary Lens Function (L-Fn) button instead. Four L-Fn buttons surround the front of the lens and these can be programmed to control a variety of lens or camera functions. This Lens is compatible with optional Extender RF 1.4x and 2x teleconverters for further extending the effective reach of this lens.