In 1996 Tokina created a new class of telephoto lens when it introduced the original AT-X 840 AF. This was the smallest zoom lens available that had a bright f/5.6 aperture at 400mm. Now Tokina has recreated the lens for the digital age.
Still the smallest SLR lens available that zooms to 400mm, the AT-X 840 AF D has a smooth and quick internal focusing system that means the all-metal inner barrel that houses the heaviest glass elements does not have to rotate when the lens focuses, making it much faster than the previous models