Tokina AT-X 11-16mm PRO DX is an ultra-wide angle lens with a fast f/2.8 aperture for better photography in low-light situations. Many photojournalists consider having an f/2.8 aperture a must for any lens in their camera bag. Based on the award-winning optical design of the AT-X 124 PRO DX (12-24mm f/4) lens, the AT-X 11-16mm PRO DX has a slightly shorter zoom range to maintain optical quality at wide apertures. Reach out if you have any questions about the item!