The AT-X 116 PRO DX-II 11-16mm f/2.8 Lens for Canon EF by Tokina is an ultra-wide angle autofocus zoom lens with a fast constant f/2.8 maximum aperture. The AT-X 116 PRO DX-II lens is designed for digital cameras with APS-C-size CMOS or CCD sensors. Its angle of view ranges from 104-84�� and it can focus as close as 11.8". Nine diaphragm blades help to produce soft out-of-focus backgrounds while two Super-Low Dispersion glass elements and two aspheric elements help to achieve excellent contrast, sharpness and minimal chromatic aberration. As an update to their AT-X 116 PRO DX, Tokina has improved the multi-layer coatings to minimize light reflection and improve optical performance. The PRO DX-II has an internal focusing motor which is ideal if shooting video with your digital camera.Tokina's One-Touch Focus Clutch Mechanism allows the photographer to switch between autofocus and manual focus with a simple push of the focus ring. Snapping it forward into autofocus and back into manual focus is all that needs be done, there's no need to adjust the AF/MF switch on the camera body.