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. Optically, the AT-X840 AF D has new multi-coatings applied to the elements that are formulated to compensate of the highly reflective CCD and CMOS sensors in today"s Digital SLR cameras. The new multi-coating greatly reduces the chance of internal flare or ghost reflections. A built-in low-profile tripod collar makes for a well-balanced camera/lens combination when using a tripod or monopod. For best results, Tokina always recommends using a tripod or monopod with telephoto lenses.