Tokina 300mm f/2.8 AT-X 300 AF PRO Telephoto Lens with Case & Hood for Canon EOS

The AT-X 300 AF PRO lens features the exclusive "Focus Clutch Mechanism.", a signature of the Tokina PRO series lenses, which provides a faster, smoother auto focus operation and a smooth manual focus action not normally found in today's auto focus lenses.

As with all the lenses in Tokina's AT-X AF series, the AT-X 300 AF PRO is constructed using all aluminum lens barrels and a chrome-plated, brass mount plate. The first lens group is made from two elements of high quality SD (super low dispersion) glass that minimizes the secondary spectrum caused by chromatic aberration. These lenses use FK01 and FK02 optical materials which gives them SD (APO) qualities.

The AT-X 300 AF PRO lens also features a patented IRF, Internal Rear Focus system. This system moves smaller lens groups within the lens barrel, which is useful for long telephoto lens designs. The IRF system has a number of advantages including faster auto focusing and more compact lens design.