The Nikon mount Tokina 12-24mm f/4 AT-X 124AF Pro DX II Lens is exclusively designed for use with SLR cameras that use Nikon's DX format (APS-C size). In addition, this updated "II" version incorporates a motor built into the lens itself, which gives it the capability to autofocus with all Nikon DSLR cameras, including the D40 and D60 series. Another benefit of the built-in motor is that focusing is quieter and more responsive. This lens provides a super wide-angle zoom range, ideal for the tightest of interiors, as well as for dramatic landscape photography. This 12-24mm f/4 AT-X version II lens also benefits from improved multi-coating technology, which helps to reduce reflections that can cause flare and ghosting. The Focus Clutch Mechanism feature - a signature of Tokina Pro series lenses - provides a faster, smoother autofocus operation, with a smooth manual focus action not normally found in autofocus lenses. Two Aspherical elements are incorporated in the lens design, to correct for spherical aberrations. It also incorporates internal focusing to prevent deterioration of the optical quality at close distances and to eliminate rotation of the front barrel during focusing. Equivalent focal length in 35mm terms when used on a digital camera is 18-36mm.