The Tokina AT-X 107 DX is a fish-eye lens that gives the photographer a 180° field of view with dramatic curvature of field or "fish-eye" effect. With this lens an entire view or vista can be captured, wider than the human eye can see. The front element of the AT-X 107 DX has a newly formulated WR or "Water Repellent" optical coating on the glass. This new coating makes marks left by water or finger-prints much easier to clean than standard multi-coating.The rear optical group of the lens contains one SD (Super-Low Dispersion) glass element to reduce the number of elements in the optical design in order to make the lens more compact, light-weight and faster focusing. This lens is for use on Nikon cameras with a DX sized sensor.