(From Tamron lens literature) Tamron USA, Inc. has announced the release of the SP AF17-50mm F/2.8 XR Di II* VC LD Aspherical [IF] (Model B005), a high speed ƒ/2.8 wide-to-moderate-telephoto zoom lens designed exclusively for Nikon-mount digital SLR cameras with smaller sensors. Featuring Tamron's proprietary tri-axial Vibration Compensation (VC) mechanism that minimizes the effects of handheld camera shake, the lens will be available starting on September 17, 2009. Tamron plans to introduce the lens in a Canon mount version shortly after the new Nikon mount version with built-in motor hits the market.
The new SP 17-50mm F/2.8 XR Di II VC covers the very popular 17-50mm focal length range (equivalent to 26-78mm in the full-frame 35mm format**) making it extremely versatile. Its wide aperture and outstanding performance provide practical advantages in low-light shooting and aesthetic image control, thereby enriching the user's range of creative expression. The new lens delivers impressive sharpness and striking contrast over its entire focal-length and aperture range, and at its maximum aperture of ƒ/2.8 it produces beautiful images enhanced by shallow depth-of- field, and smooth, natural transitions in out-of-focus areas of the image (i.e. excellent bokeh.) The new lens is equipped with Tamron's proprietary Vibration Compensation (VC) image stabilization mechanism, which controls the effects of camera shake in three planes. VC provides more opportunities for sharp hand-held photography at the slow shutter speeds needed when shooting in low-light conditions (e.g. night or indoor scenes) dramatically enhancing the user's level of photographic freedom.
The previously announced, still currently available Tamron SP 17-50mm F/2.8 XR Di II (Model A16) boasts superlative optical performance for a fast standard zoom lens and has been acclaimed world-wide as a masterpiece of compact optical design. In developing the new Tamron SP 17-50mm F/2.8 XR Di II VC zoom, the primary goal was to maintain this incredible compactness and ease-of-use while simultaneously enhancing its convenience and expanding its performance envelope. As a result of concerted efforts, the engineers were able to incorporate Tamron's proprietary state-of-the-art Vibration Compensation (VC) image stabilization mechanism into the new lens without materially increasing its size and weight. As a result of this success, the SP 17-50mm F/2.8 XR Di II VC makes sharp hand-held photography possible under a vastly expanded range of photographic situations.
The Tamron Vibration Compensation mechanism employs a three-coil system in which three driving coils move internal optical components within the VC lens electromagnetically, based on signals originating from three steel ball bearings. Since the VC compensating lens elements are held in place solely by contact with these bearings, smooth, virtually frictionless movement is assured, providing the stabilized viewfinder images and excellent tracking performance characteristic of VC lenses. Moreover, since the VC lens elements move parallel to the image plane via electronic control alone, the mechanical structure is simplified, and the lens is more compact.
*Di (Digitally integrated)-II lenses are designed for exclusive use on digital cameras with smaller-size imagers. This lens is not designed for use with 35mm film cameras or digital SLR cameras with image sensors larger than 24mm x 16mm.
**Tamron's conversion value is 1.55x
