The large angle of view of the Sigma 12-24 4.5/5.6 EX DG ASPH Zoom (122 degree super wide angle of view at 12mm along the diagonal axis) is ideal for shooting indoors as well as landscape photography. It has a variable angle of view from 122 degrees to 84.1 degrees.
Four Special Low Dispertion (SLD) glass elements are provided for effective compensation of color aberration, which is a common problem with super-wide angle lenses. Two pieces of Glass Mold and one-piece Hybrid aspherical lenses offer excellent correction for distortion as well as all types of aberration.
By effective arrangement of lens elements and advanced technology this lens has Super Compact dimensions of 100mm full-length, and 87mm Maximum Diameter. It is equipped with an Inner Focusing System that will keep the length of the lens unchanged, while controlling aberration.
The models which are equipped with the HSM (Hyper Sonic Motor) System (only in Nikon, Canon and Sigma Camera Mounts) offer Full Time Manual Focusing. It has a minimum focusing distance of 28mm at all focal lengths. This lens is equipped with an integral Petal-Type Hood, to block out extraneous light.