Sigma 18-50mm f2.8 is specially designed to suit the characteristics of digital SLR cameras and provides a high level of optical performance. It has a large aperture of F2.8 throughout the entire zoom range, offers superior peripheral brightness as well as a compact and lightweight construction. A maximum magnification of 1:3, making it ideal for close-up photography. A minimum focusing distance of 20cm (7.9), a maximum magnification of 1:3 This large aperture standard zoom lens, with close-up ability, is ideal for portrait and snap shots. Large aperture of F2.8 throughout the entire zoom range Large aperture enables easy confirmation of focusing from bright viewfinder. This lens is perfectly suited for low light conditions indoors or at dusk. Excellent optical design Special Low Dispersion (SLD) and Extraordinary Low Dispersion (ELD) glass elements provide excellent correction of color aberrations. This lens produces an exceptional level of optical performance. Compact and lightweight lens Its design incorporates both glass-mold and hybrid aspherical lens technology which offers a compact and lightweight construction. Reduced Ghosting and Flare The super multi-layer lens coating reduces flare and ghost. High image quality is assured throughout the entire zoom range. Inner Focus System An inner focusing system eliminates front lens rotation, making the lens particularly suitable for using the petal-type lens hood (supplied) plus circular polarizing filters.