The Tokina 11-16mm f/2.8 AT-X 116 Pro DX Lens is an ultra wide angle, short zoom range lens specifically designed for use with Canon APS-C digital SLR cameras. The slightly shorter zoom range of this lens over the popular and award winning 12-24mm lens makes it possible to maintain optical quality even at wide-open apertures. This lens features a fast constant aperture of f/2.8, and provides a focal length equivalent to 17-25mm in 35mm format.
As part of the AT-X line, this lens is designed to provide excellent optical quality, and offers advanced features like the WR (Water Repellent) front element, its One-touch Focus Clutch Mechanism, that 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 second AF/MF switch on the lens for Canon, everything is accomplished by the focus ring), and a 9-bladed aperture. This is an excellent lens for short closeup photography.
WR (Water Repellent) coating made of a special compound has been applied to the front surface of the lens through the use of a unique evaporation process. As a result, the lens offers excellent water- and oil-repellent performance and makes for easier cleaning should the lens be accidentally smeared with fingerprints or cosmetics.
One Touch Focus Clutch Mechanism
The One Touch Focus Clutch Mechanism allows for fast and easy switching between manual and auto focus from any position. This improvement means that it is not necessary to change the AF/MF switch (on the body with Nikon or the lens with Canon) every time the lens is changed from auto focus to manual focus mode.
The rounded diaphragm opening (9 blades) makes out-of-focus elements appear more natural.