- 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.
- Dual Nano USM system uses both a ring type USM and an STM mechanism to realize quick and accurate focusing. The smooth and nearly silent focusing suits both photography and video applications and there is full-time manual focus control available.
- 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.
- Weather-sealed design enables working in harsh environments and prevents dust and moisture from reaching the interior of the lens. Also, there is a front fluorine coating that prevents water, oils, and other residue types from sticking to lens, making it easier to clean.
- Impressively lightweight for its speed and zoom range, this lens weighs 5.8 lb and measures 12.7" long.
- Internal focusing and zooming design maintains the overall length of the lens during operations and promotes quicker operations and more robust weather sealing.
- Built-in rotating tripod mount suits working with the lens atop a monopod or tripod and enables quick switching between vertical and horizontal shooting orientations.
- 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.
- Programmable Control Ring can be used for lens-based adjustment of various exposure or camera settings and comes with a click-stop operation by default for tactile feedback.
- Compatible with optional Extender RF 1.4x and 2x teleconverters for further extending the effective reach of this lens.