An Air Sphere Coating (ASC) has been applied to lens elements to reduce backlit flaring and ghosting for maintained light transmission and high contrast in strong lighting conditions.

A ring-type Ultrasonic Motor (USM), along with optimized focusing algorithms and a high-speed CPU, is employed to deliver fast, precise, and quiet autofocus performance as well as full-time manual focus override.

Optical image stabilization minimizes the effects of camera shake by compensating for up to four stops of shutter speed.

Rounded nine-blade diaphragm contributes to a pleasing out of focus quality that benefits the use of shallow depth of field and selective focus techniques.

As a member of the esteemed L-series, this lens is sealed against dust and moisture for working in inclement environmental conditions.

Fluorine-coating on exposed elements affords protection to the optical system, resists smudging and fingerprints, and is easier to clean.

Wide-angle zoom lens is designed for use with full-frame Canon RF-mount mirrorless cameras.

Constant f/4 maximum aperture maintains consistent illumination throughout the zoom range.

An Optical Image Stabilizer helps to minimize the appearance of camera shake by 5.5 stops to better enable working in low-light conditions and with slower shutter speeds.

Up to 7 stops of correction when used on EOS R-series cameras with In-Body Image Stabilization.

Nano USM system utilizes both a ring type USM and an STM mechanism to realize quick and accurate focusing that is also smooth and nearly silent to suit both photography and video applications. This focusing system also affords full-time manual focus control when working in the one-shot AF mode.

Configurable Control Ring can be used to adjust a variety of exposure settings, including aperture, ISO, and exposure compensation.

As a member of the esteemed L-series, this lens has a weather-resistant design that protects against dust and moisture to enable its use in inclement conditions.

One Super ED element and two extra-low dispersion elements are featured in the lens design and help to reduce chromatic aberrations and color fringing for improved clarity and color neutrality.

Nano AR Coating II has been applied to reduce surface reflections, flare, and ghosting for increased contrast and color rendering in strong lighting conditions. This updated coating is better suited for larger, curved elements and is especially adept at minimizing internal reflections.

An XD Linear Motor system uses two separate motors, along with an internal focusing design, to provide quick, quiet, and precise autofocus and tracking performance. This design also contributes to more natural, intuitive Linear Response manual focus control and an AF/MF switch is located on the lens barrel for quick focus mode switching.

Minimum focusing distance of 9.8" suits making dynamic close-up images.

A focus hold button is present on the lens barrel for intuitive tactile control and rapid access to select programmable settings.

Physical aperture ring can be de-clicked for smooth, silent aperture switching to benefit video applications. The ring also incorporates a locking "A" position for use in automated exposure modes.

Dust- and moisture-sealed design better permits working in inclement conditions and rubberized control rings benefit handling in colder temperatures.

Fluorine-coated front and rear elements resist dust, moisture, and fingerprints and are easy to clean.

Filter holder is incorporated at the rear of the lens, within the lens mount, and accepts cut gel filters and a filter cutting template is included.

Integrated petal-shaped lens hood helps to block stray light from causing lens flare and also affords some physical protection to the front element.