A ring-type Ultrasonic Motor (USM), along with an internal focusing system, is employed to deliver fast, precise, and quiet autofocus performance as well as full-time manual focus override.
Focus Limiter switch lets you constrain the focusing to two different ranges to suit different applications: 3.9′-infinity or 8.2′-infinity.
A weather-resistant design protects the lens from dust and moisture to enable its use in inclement conditions. Additionally, fluorine coatings have also been applied to the front and rear lens elements for further protection against fingerprints and smudging.
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.