Tokina AT-X 16-28mm f/2.8 Pro FX Lens for Nikon

 Designed for full frame (FX) nikon DSLR, silent DC motor with GMR sensor, 15 elements in 13 groups, aspherical, super-low dispersion glass. Easily switch from auto to manual focus for the professional a 16-28 mm f/2.8 lens is almost a necessity and this new lens for nikon from tokina fills the bill very nicely. This super wide-angle zoom has 15 elements in 13 groups using a-spherical and SD super-low dispersion glass elements to reduce chromatic aberration and give maximum resolution. The silent DC motor allows the lens to focus quickly and quietly and works with a GMR magnetic AF sensor to increase AF speed even more. An exclusive one-touch focus clutch mechanism allows switching quickly between auto focus and manual focus by snapping the focus ring forward for AF and back toward the camera for manual focus. And it's possible to buy this lens without applying for a mortgage first.

 NEW Silent DC Motor with GMR senor 
The 16-28mm f/2.8 lens 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. With a motor this quiet you can film videos with the confidence of knowing the sound quality won't be ruined by the buzzing of an older, more traditional lens motor.

Aspherical and Super-low Dispersion glass elements 
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. 

One-Touch Focus Clutch 
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 manually. There is no need to change the AF/MF switch on Nikon camera bodies* and there is no second AF/MF switch on the lens for Canon, everything is accomplished by the focus ring.

Specifications

• Focal Length 16 - 28mm
• Aperture Maximum: f/2.8
• Minimum: f/22
• Camera Mount Type Nikon F
• Format Compatibility
• Nikon FX/35mm Film, Nikon DX
• Angle of View 107° - 76°
• Minimum Focus Distance 11" (27.94 cm)
• Magnification 0.19x
• Maximum Reproduction Ratio 1:5
• Elements/Groups 15/13
• Diaphragm Blades Not Specified By Manufacturer
• Image Stabilization No
• Autofocus Yes
• Tripod Collar No
• Filter Thread None
• Dimensions (DxL) Approx. 3.54 x 5.25" (8.99 x 13.34 cm)
• Weight 2.09 lb (950 g)