An Optical Image Stabilizer helps to minimize the appearance of camera shake by up to four shutter speed stops to better enable working in low-light conditions and with slower shutter speeds. Three distinct IS modes are available: standard single-shot mode, a panning-optimized mode, and a mode that only activates the Image Stabilizer during the exposure.

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.

Focus Preset function is available to quickly recall a programmed focusing position.

Focus Limiter switch lets you constrain the focusing to three different ranges to suit different applications.

A Power Focus setting is available, and allows you to electronically and smoothly adjust your focus position to suit video recording. This setting utilizes a dedicated ring in front of the main focusing ring and allows you to use one of two different focusing speeds.

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.

Removable rotating tripod collar is included and benefits working with the lens atop a tripod or monopod.

Compatible with optional EF 1.4X and EF 2X teleconverters.

Vibration Reduction image stabilization helps to reduce the appearance of camera shake to better enable handheld shooting in low-light situations.

Multi-focus system incorporates two separate AF drive units, which are synchronized, to deliver especially fast and accurate focusing throughout the zoom range. This system uses stepping motors, which offer impressively smooth and quiet autofocus performance that is well-suited to both stills and video applications. Full-time manual focus override is also possible and an internal focusing design is used, where only the internal lens groups are moved during focusing, to maintain the overall length of the lens during use and to promote faster focusing speeds.

Programmable Control Ring is, by default, set to adjust manual focus, but can also be used to control aperture or exposure compensation.

Integrated OLED lens information panel allows you to quickly confirm aperture setting, focus distance, and depth of field figures right on the lens in both bright and dark situations.

Two assignable L.Fn buttons work in conjunction with camera-based Fn buttons to provide seamless points for quickly changing exposure settings and other functions.

Specialized electromagnetic aperture mechanism provides greater exposure control stability that is especially beneficial when working with fast continuous shooting rates.

Dust- and moisture-resistant lens barrel, along with a front fluorine coating, benefits the lens' use in inclement conditions.

Removable, rotating tripod collar spins on ball bearings to permit quick and smooth switching from vertical to horizontal shooting orientations.