To experience the ultimate in wide-angle photography, the EF 11-24mm f/4L USM brings L-series construction and optics to the widest zoom lens Canon has ever made. With an expansive wide-angle range of 11-24mm, this is an ideal lens for landscapes, interior shots, and unique perspectives on subjects close and far. Its new optical design features Super UD and UD lenses that correct chromatic aberration. Four aspheric lens elements help to minimize distortion from the center of the image to the periphery and throughout the zoom range. A Subwavelength Coating (SWC) and Air Sphere Coating (ASC) significantly reduce flare and ghosting, while a 9-blade circular aperture diaphragm creates beautiful, blurred backgrounds. For silent and fast AF, it features a rear focus system and ring USM, and can be manually focused even when in AF mode. It has a minimum focusing distance of 11 in./0.28m (extreme telephoto) for admirable performance and results even when shooting in tight spaces.