|Lens type||Zoom lens|
|Max Format size||35mm FF|
|Focal length||80–400 mm|
|Lens mount||Canon EF, Nikon F (FX)|
|Number of diaphragm blades||8|
|Special elements / coatings||SD glass element|
|Minimum focus||2.50 m (98.43″)|
|Motor type||Screw drive from camera|
|Full time manual||Yes|
|Focus notes||Canon version includes AF micromotor|
|Weight||1020 g (2.25 lb)|
|Diameter||79 mm (3.11″)|
|Length||137 mm (5.37″)|
|Zoom method||Rotary (extending)|
|Filter thread||72 mm|
|Hood product code||BH-725|
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.