The Tokina 14-20mm f/2 AT-X PRO DX, Canon EF-S Fit is an new wide angle lens for APS-C sized (cropped) sensors. Super-fast F2 aperture, the fastest lens ever made by Tokina, provides 21 to 30mm focal length in 35mm equivalency. The 14-20mm F2 has an all-new proprietary optical design that uses three aspherical lens elements (2 all-glass molded and 1 hybrid) to achieve superior contrast, sharpness, and correct for spherical aberrations. Additionally, Tokina uses of an four SD (Super-low Dispersion) glass elements to control chromatic aberrations. The super-bright, constant F2.0 aperture of the Tokina 14-20mm makes viewing, auto focus and shooting possible in very low light situations while still maintaining reasonable size and weight. Furthermore the One-Touch Focus Clutch Mechanism allows the photographer to switch between AF and MF with ease. The advanced features and Tokina's normal, superior build it make it a must have lens for many photographers. This lens is in good overall condition with some signs of use. The glass is clean and in good condition. The lens barrel shows some cosmetic marks. There is some light dust within the lens, which would not affect optical performance at all. The focus ring is in good condition. The lens mount shows signs of use.Please Note: There are marks to the internal element, this has no discernible effect on the image rendered.