The new Tokina AT-X 116 PRO DX is an ultra-wide angle lens with a fast f/2.8 aperture for better photography in low-light situations. Many photojournalists consider having an f/2.8 aperture a must for any lens in their camera bag.
Tokinas exclusive One-touch Focus Clutch Mechanism allows the photographer to switch between AF and MF simply by snapping the focus ring forward for AF and back toward the camera to focus manually. There is no need to change the AF-MF switch on Nikon cameras** and there is no second AF/MF switch on the lens for Canon, everything is accomplished by the focus ring.