The Tokina 11-16mm f/2.8 is an ultra wide angle, short zoom range lens. 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 16.5-24mm in 35mm format. 

Tokina 11-16mm f/2.8 AT-X 116 Pro DX AF Lens