This ultra-wide zoom lens has a wide angle of view from 102.4 - 63.8 degrees (when Sigma mount is used) and it is exclusive to digital SLR cameras. SLD glass elements effectively compensate color aberration. Aspherical lenses provide maximum correction for distortion and various aberrations; high image quality is displayed throughout the entire zoom range. The HSM equipped models makes fast AF speeds and quiet shooting a reality, and it is also capable of full-time manual focus. It has a minimum focusing distance of 24cm (9.4 inch) at all focal lengths. It is also equipped with an integral Petal-type hood to block out extraneous light.