A ring-type Ultrasonic Motor (USM), along with an internal focusing system, high-speed CPU, and optimized AF algorithms, are employed to deliver fast, precise, and near-silent autofocus performance as well as full-time manual focus override.

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

Protective fluorine coating has been applied to the front bulbous element to resist fingerprints and smudges and to make cleaning significantly easier.

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.

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.