Manufacturer description: This Sigma 12-24mm F4.5-5.6 EX DG Aspherical lens is a result of Sigma’s reputation for consistently producing outstanding wide angle and super wide angle lenses. This lens incorporates an amazing range of popular focal lengths covering angles of view from approximately 85º up to 122º. This kind of scope makes this lens critical for landscape and scenic photography and can also be an amazing performer for interior and exterior architectural shooting. Three Aspherical glass elements offer correction for distortion and four SLD (Special Low Dispersion) glass elements employed for effective compensation of color aberration. It is also perfect for press or social situations where the photographer often has no control of the distances and size of the subject groups.