The EF 50mm f/1.4 USM is a consumer- and professional-level lens. It is the least expensive f/1.4 aperture lens that Canon currently manufactures. It is constructed with a plastic body and a metal mount. This lens features a distance window with infrared index. An 8-blade diaphragm and maximum aperture of f/1.4 give this lens the ability to create shallow depth of field effects. The optical construction of this lens contains 7 lens elements, without any special lens elements. The lens uses a front extension focusing system, powered by a micro USM motor. Even though this lens uses a micro USM motor, it still has FTM (full-time manual focus) available. Auto-focus speed of this lens is fast, but not as quick as most ring-USM-based lenses. The front of the lens does not rotate, but extend up to about one centimeter when focusing.
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