The Sigma 18-200mm f/3.5-6.3 II DC OS HSM Lens for Pentax AF offers an "all-in-one" super-zoom lens solution, from wide-angle to long telephoto. It provides the equivalent focal range of approx. 27-300mm when used with a Pentax digital SLR camera with an APS-C size sensor*. It includes a Hyper Sonic Motor (HSM) for quiet, high-speed autofocus. The 18-200mm's optical design incorporates aspherical lenses, with FLD and SLD glass, which provides the utmost correction for color 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 APS-C image sensor found on many digital cameras. As a result these lenses are also more compact and lightweight, and are better matched to digital SLR cameras. This DC (Digital) lens is designed so that the image circle matches the smaller size of the image sensor of most digital SLR cameras. Its specialized design gives the lens the ideal properties for digital cameras; the compact and lightweight construction is an added bonus.Two Special Low Dispersion (SLD) elements and three hybrid aspherical lenses provide high-quality images throughout the entire zoom range.FLD glass provides excellent correction of color aberration.Super Multi Layer (SML) coating reduces ghost and flare.The HSM (Hyper Sonic Motor) ensures quiet, high-speed autofocus and the inner focus system eliminates front lens rotation, making the lens particularly suitable for using the supplied petal-type lens hood and circular polarizing filters.A magnification scale is displayed on the lens barrel for each focal length, ensuring ease of
