A flexible zoom distinguished by its relatively lightweight and compact design, the EF 70-200mm f/4L USM is a Canon L-series optic spanning a useful portrait-length to medium telephoto range. The constant f/4 maximum aperture allows you to maintain a consistent exposure throughout the zoom range and also contributes to the sleeker form factor when compared to other 70-200mm lenses. In regard to its optical performance, this lens employs one fluorite element and two ultra-low dispersion elements, which work in concert to suppress chromatic aberrations and color fringing for notable clarity and color accuracy. A Super Spectra coating has also been applied to control flare and ghosting for improved contrast when working in harsh lighting. Complementing the optical attributes, this lens also features a ring-type USM and internal focusing mechanism for quick, quiet, and accurate autofocus performance, as well as full-time manual focus override. Versatile telephoto zoom is designed for full-frame Canon EF-mount DSLRs, however can also be used with APS-C models where it provides a 112-320mm equivalent focal length range. Constant f/4 maximum aperture affords consistent performance throughout the zoom range and also contributes to the relatively lightweight design and compact form factor. One fluorite element and two ultra-low dispersion glass elements noticeably reduce color fringing and chromatic aberrations for high clarity and color fidelity. Super Spectra coating has been applied to individual elements to minimize ghosting and flare for greater contrast and color neutrality when working in strong lighting conditions. 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 9.8'-infinity. Rounded eight-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. Optional rotating tripod collar is available and benefits working with the lens atop a tripod or monopod. Compatible with optional EF 1.4X and EF 2X teleconverters.