The Sigma 8-16mm F4.5-5.6 DC HSM is the only one of its kind. It is the first ultra wide zoom lens with a minimum focal length of 8mm, designed specifically for APS-C size image sensors. It has an equivalent angle of view of a 12-24mm lens when used on digital camera with an APS-C size image sensor. FLD glass elements, which have the performance equal to fluorite glass, compensate for chromatic aberration. One hybrid aspherical lens and two glass mold elements deliver superior correction for distortion and astigmatism. The inner focusing system produces high definition images throughout the entire zoom range. Its Super Multi-Layer Coating minimizes flare and ghosting while superior peripheral brightness ensures high contrast images throughout the entire zoom range. HSM ensures quiet and high speed AF as well as full-time manual focus capability. It has a minimum focusing distance of 9.4 inches throughout the entire zoom range which allows photographers to emphasize the subject by creating exaggerated perspectives. This lens is perfect for shooting landscape photography, architecture, building interiors, and much more!