The Sigma 18-200mm f/3.5-6.3 DC OS (Optical Stabilizer) Lens offers an "all-in-one" super-zoom lens solution, from wide-angle to long telephoto. It provides the equivalent focal range of approx. 29-320mm when used with a Canon digital SLR camera(*). This lens has now been updated with the OS (Optical Stabilizer) system, which minimizes image blur caused by camera shake, and offers the equivalent of shooting at a shutter speed 2-3 stops faster. This allows handheld telephoto zoom shooting even in poorly lit conditions. The 18-200mm's optical design incorporates aspherical lenses and SLD (Special Low Dispersion) glass, which provides the utmost correction for all types of aberrations. It also enables this extended super-zoom lens to be housed in a compact and lightweight construction. DC lenses are exclusively designed for digital SLR cameras. The image circle (rear of lens) is sized to match the smaller dimensions used for the image sensor on digital cameras. As a result these lenses are also more compact and lightweight, and are better matched to digital SLR cameras. Note: (*) Not suitable for 35mm film SLR cameras or for any digital SLR camera with image sensor bigger than APS-C size, e.g. 1D series or Kodak Pro SLR/c.