This ultra-wide angle lens is designed for use with digital SLR cameras such as the Nikon D100, which have smaller sized sensors. Its 17mm image is equivalent on the D100 to 24mm. The lens can also be used on a conventional SLR film camera to produce a full frame ultra- wide angle view
A very good quality lens at a competitive price when I bought it of £399, it doesn't quite match up to the sharpness and brilliance of Nikkor lenses.
Camera accessories> Lenses > Sigma 17-35mm Zoom
Lenses, Sigma, wide-angle