High-Performance, High-Speed Telephoto Zoom Combining the versatility of a zoom with the reach and speed of a cherished telephoto concept, 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. Zoom Evolution Building on the legacy of the popular EF 300mm f/2.8 prime lenses, 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. 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. Wholly new optical design includes fluorite elements and ultra-low dispersion glass, plus one aspherical element, to achieve a higher degree of clarity and sharpness with virtually no distortion. Canon's Air Sphere Coating (ASC) and Super Spectra Coating (SSC) minimizes ghosting and flare to better enable working in backlit conditions or when facing strong lighting situations.