The Canon EF 24mm f/1.4L II USM Lens lens is a venerable wide-angle prime lens that provides sharpness and impressive performance at all settings. Its large maximum aperture of f/1.4 allows for superb low-light photographs, and its circular aperture and narrow depth of field provide pleasing background blur. It is the ideal tool for photojournalists, landscape and event photographers, and anyone who enjoys taking images from a wider perspective.This version "II" improves greatly over its predecessor with the addition of two high-precision aspheric lenses, which correct aberration including curvature of field and distortion. Chromatic aberration common in wide-angle shooting is also reduced by the inclusion of two UD lenses, which ensure optimum image quality and corner-to-corner detail.The EF 24mm f/1.4L II USM features Canon's near-silent Ultra Sonic Motor (USM), which provides super-fast auto-focusing with full-time manual override. The floating internal focus system also helps maintain high image quality throughout the focal range.SWC (Sub Wavelength Coating)The anti-reflective SWC (Sub Wavelength Coating) differs from conventional coatings by using a much finer structure, which minimizes ghosting and flaring across the lens surface, regardless of the angle with which light enters or exits.Ring-Type USM MotorCanon's very best autofocusing mechanisms are in place, permitting full-time manual focusing override without requiring a switchover from AF to MF mode.L-SeriesCanon's "L-Series" designation indicates that this lens meets their highest quality standards with excellent color reproduction and edge to edge sharpness.