Tokina 17-35mm f/4 SD AT-X PRO
Center sharpness is very good, even fully open, but on FX, edges are soft when it is used fully bore and need stopping down to about f/5.6 to be acceptable. Distortions are almost non-existent, much better than most wide angle zooms. There is barely visible barrel distortion at the wide end, and even less pincussion at the tele end. Both are easy to correct in Panorama Tools or Photoshop's distortion filter. There is visible vignetting wide open at 17 mm. Somewhat prone to flare and ghosting. CA seems to be well controlled.
Mechanically, the lens is not a professional grade lens, but the mount is metal, and it feels solid. The gear-driven AF is noisy, but fairly responsive. No manual override in AF-mode, but you may shift quickly between MF and AF by pulling and pushing the focus ring.
Comes with plastic bayonet BH-821.
Rating: Ed: -, User: - (normalized, 0=useless, 50=average, 100=excellent).
Mounts: Canon EF, Nikon F.
Aperture range: f/4 to f/22.
Optical zoom: 2.1x.
Close focus distance (CFD): 28 cm / 0.92 ft (from sensor plane).
CFD magnification: 1:4.8 / 0.21X.
Focus: AF (built-in, unknown type).
Filter diameter: 82 mm.
L x D, W: 95 x 89 mm, 600 g.
Approximate street price: USD 669 (new, w/o tax).
The Tokina brand is used by the Kenko-Tokina group for lenses, filters and CCTV equipment. Tokina started out as an independed company founded in 1950 as Tokyo Optical Equipment Manufacturing by a group of former Nikon engineers. It was renamed Tokina Optical Co. Ltd. in 1971 and Tokina Co. Ltd. in 1995. In June 2011, Tokina merged with its distributor Kenko to form Kenko-Tokina. Until then, Tokina was the smallest of the Japanese independent lens makers.
The corporate relationship between Kenko-Tokina and another Japanese optical industry, Hoya, is unclear. Kenko-Tokina and Hoya promote each others products. In the USA, Tokina, Hoya and Kenko-branded products are distributed by the same company (THKphoto.com).
An obscure brand of flash units, Woctron, is also distributed by Kenko-Tokina.