Built in motor for use on the new Nikon Cameras Includes lens hood, 67mm filter size 2.9 inches in diameter and 3.2 inches long Wide Angle To Standard Zoom The SP AF17-50mm F/2.8 is a lightweight, compact, fast standard zoom lens designed exclusively for digital SLR cameras, expanding the product concept of the popular SP AF28-75mm F/2.8 zoom lens. In addition, portrait shots are made beautiful with the natural out-of-focus effect characteristic provided by the fast F/2.8 aperture. Additionally, a broader photographic expression through the use of faster shutter speeds as a result of the maximum aperture offers enhanced photographic pleasure. The lens boasts one of the best close-up shooting performances in the class of fast standard zoom lenses designed exclusively for digital cameras and featuring an F/2.8 maximum aperture throughout the entire zoom range, to ensure stress-free photographic shots at all focal lengths and distances. Extraordinary detail at the macro level AF17-50mm F/3.5-6.3 XR Di II Highlights Di II Lenses are designed for exclusive use on digital cameras with smaller-size imagers and inherit all of the benefits of our Di products. These lenses are not designed for conventional cameras and digital cameras with image sensors larger than 24mm x 16mm. Extra Refractive Index Glass (XR) Extra Refractive Index (XR) glass can bend light rays at steeper angles, thereby decreasing the physical length of the lens while enhancing imaging performance by minimizing optical aberrations. This has allowed Tamron to develop a line of shorter, smaller-diameter, lighter lenses without sacrificing lens speed, and actually upgrading image quality compared to older designs. XR glass is costlier than conventional glass but it yields enhanced optical power distribution, making possible many of the outstanding and innovative lens designs that bear the XR designation.