The Tokina atx-i 11-20mm F2.8 CF is designed as an ultra wide angle zoom lens for APS-C sensor DLSR cameras. It is the only f/2.8 fast ultra wide angle zoom lens for APS-C sized DSLR cameras in the current market. Focal length 11-20mm that covers equivalent angle of wide prime 18mm, 21mm, 24mm, 28mm lenses makes this lens attractive to be chosen after standard zoom lens or initially possessed wide angle zoom kit lens. A constant maximum aperture of f/2.8 throughout the entire zoom range is realized to achieve great results in low light conditions, for depth of field control and easy manual shooting, while maintaining a reasonable size and weight.