The Tokina AT-X 107 NH is a fish-eye lens that gives the digital photographer an approximate 180 degree field of view with dramatic curvature of field or “fish-eye” effect. The AT-X 107 NH only differs from the AT-X 107 DX in that the built-in hood as been removed allowing for a wider image area and more coverage on full-frame sensor (FX) cameras. (Full corner to corner image can be achieved on an FX camera between approx. 14.5-17 mm depending on the camera model, at 10-14 mm there is a semi-circular view.) The front element of the AT-X 107 DX has a newly formulated WR or “Water Repellent" optical coating on the glass. This coating makes marks such as spots left by water or finger-prints much easier to clean than standard multi-coating. With the built-in hood removed the lens also fits in a wider variety of underwater housings. The rear optical group of the lens contains 1 SD (Super-Low Dispersion) glass element to reduce the number of elements (pieces of glass) in the optical design in order to make the lens more compact, light-weight and faster focusing.