The EF 70-200mm f/4L IS II USM from Canon is an impressively versatile telephoto zoom. Well-suited for a range of subjects, from events to portraiture to sports, this zoom is characterized by its constant f/4 maximum aperture to strike a balance between consistent performance and portability. Its optical design includes a pair of UD elements and one fluorite element to greatly reduce chromatic aberrations and color fringing. A ring-type USM and internal focusing mechanism also afford quick, quiet, and accurate autofocus performance, as well as full-time manual focus override. Additionally, this lens is weather-sealed for use in trying environmental conditions. Constant f/4 maximum aperture affords consistent performance throughout the zoom range and also contributes to the relatively lightweight design and compact form factor. 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. 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.
Canon EF 70-200mm F/4L IS II USM Specs