The Canon Ef 70-200mm f/2.8L Usm lens is a wide-aperture telephoto zoom designed for professional photographers and advanced hobbyists. It's one of the most popular telephoto zoom lenses in the world. Designed to work with both full-frame and Aps sensor Canon DSLRs, this fast autofocus high-performance lens includes four Ud glass elements, which promote contrasty, accurate images. The wide constant f/2.8 maximum aperture provides shallow depth of field so the subject is better separated from the background. A focus range limiter helps reduce focus time. Its ultrasonic motor focuses quickly and smoothly. Minimum focus is 4.9 feet. A removable tripod collar is included. What you should know about this lens: Compatible with tele extenders: You can increase this lens's range--The lens is compatible with the Canon Extenders Ef 1.4x and 2x Ii.