This amazing Canon 2045B002 camera lens fits a great spot in the ultra-wide angle lens market. These lenses have always been in high demand by architectural, corporate, and other top pro photographers, and this lens is no exception. It features completely redesigned optics, including two high-precision aspherical elements and two completely new UD-glass elements. The result is a superior image, with better contrast and sharpness at the outer edges, as well as a reduction in chromatic aberrations. Its diagonal view angle is just short of a fisheye lens. Its included lens hood is an added bonus, and it is dust and moisture-roof. The lens uses a rear focusing system, built in high-speed CPU, and a powerful ring-type USM with revised electronics for a faster, more responsive AF. This lens continues the proud tradition of superior clarity optics found in L-series Canon lenses.