The AT-X 116 PRO DX-II 11-16mm f/2.8 Lens for Canon Mount 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. A constant f/2.8 maximum aperture benefits working in low-light situations and also aids in creating a shallow depth of field. An internal focusing motor allows for smoother focus transitions and is ideal for shooting video with your digital camera. Two Super-Low Dispersion glass elements and two aspheric elements, as well as improved multi-coating, achieve excellent sharpness and contrast and reduce aberrations. The One-Touch Focus Clutch Mechanism offers a simple switch from manual focus to autofocus and back again. The focus ring snaps forward for AF and back for MF. It's operable with one hand and eliminates the need to switch from AF to MF on the camera body.