Tokina AT-X SD 80-200mm f/2.8 is telephoto zoom lens with razor sharp optics and maintains constant lens speed for most autofocus 35mm SLR cameras. This is a professional lens incorporates high definition SD glass elements to eliminate chromatic aberrations. The lens remains stable and dependable while performing extremely well under a wide range of photographic conditions. The floating element system focuses two different element groups providing faster speed and consistent high image quality from 1.8m close focus to infinity. Additionally, the lens sports 17 elements in 11 groups (including SD glass elements to eliminate chromatic aberrations), six blade diaphragm, 30.2-12.3° viewing field, 77mm filter thread and internal focusing system.