The Sigma 12-24mm F4.5-5.6 EX DG Aspherical HSM Lens has a super wide-angle of 122° when used with a 35mm or full-frame digital SLLR camera. The zoom range of this lens makes it ideal for the tightest of interiors, as well as for dramatic landscape photography.
Using effective arrangement of lens elements and advanced technology this lens has super compact dimensions of only 3.9 inches full-length, and 3.4 inches 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 HSM (Hyper Sonic Motor, available for Sigma, Canon and Nikon camera mount lens) system offer Full Time Manual Focusing.
The super wide angle of this lens also makes it ideal for use with digital SLR cameras, providing a focal zoom range of approximately 19-38.5mm.
NOTE: HSM lenses, while able to manually focus with all Nikon F-mount cameras, will autofocus ONLY with the following cameras- F6, F5, F4s, F100, N90s, N90, N80, N75, N70, N65, D1 & D2-series, D50, D70, D100, Pronea 6i, and Pronea S (or newer camera models). With other models, HSM or AF-S lenses must be focused manually. This is the same limitation as Nikon's own AF-S lenses.