Sigma 18-50mm F/3.5-5.6 DC Lens for Canon EOS Digital SLR Cameras The use of aspherical lenses provides correction for various aberrations and makes high quality images a reality throughout the entire zoom range. The use of aspherical lenses provides correction for various aberrations throughout the entire zoom range and produce high level of optical performance. Exclusively designed to suit the characteristics of digital SLR cameras. The image circle was designed to match the size of the image sensors of most digital SLR cameras and this has resulted in a compact lightweight lens. We took digital characteristics into consideration when designing the lens power layout and created the most suitable lens that makes high quality images a reality throughout the entire zoom range. We used the the most appropriate coating for digital products to cut down flare and ghost caused by digital SLR cameras and to produce the best color balance. It can be used with the supplied lens hood to block out extraneous light. The 18-50mm f/3.5-5.6 DC zoom lens has a minimum focusing distance of 25cm (9.8 in.) at all focal lengths and is capable of macro photography with a maximum magnification ratio of 1:3.5. The focus ring provides easy operation in manual mode. A distance scale on the focus ring is an easy to use and convenient addition.