The 16-28 zoom range gives the professional photographer a super-wide angle of view to get close to subject for dramatic effect or to take in entire scenes. The 16-28 f/2.8 uses a newly developed silent DC motor that allows the lens to focus faster and more quietly then previous generations. The DC motor coupled with a new GMR magnetic AF sensor work together to increase AF Speed.
A new, 56mm in diameter, large sizes aspherical glass element is incorporated into the front lens group, while there are 2 more aspherical elements in the rear group. 3 SD super-low dispersion glass elements are also incorporated through-out the optical design to reduce chromatic aberration, give maximum resolution, more even brightness and distortion correction.
Tokina’s exclusive One-touch Focus Clutch Mechanism 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