The Tamron AF 17-50mm f/2.8 XR Di II LD is a lightweight, compact, fast standard zoom lens designed exclusively for digital SLR cameras. This lens has a focal length of equivalent to approx. 26-78mm in 35mm format. The Tamron AF 17-50mm f/2.8 XR Di II LD offers an f/2.8 maximum aperture throughout the entire zoom range, and this ensures stress-free photographic shots at all focal lengths and distances. In addition to that, the Tamron AF 17-50mm f/2.8 XR Di II LD delivers a broader photographic expression through the use of faster shutter speeds as a result of the maximum aperture offers enhanced photographic pleasure.