The Sigma 18-50mm f/2.8 EX DC Autofocus Zoom Lens is part of the EX Series, which combines excellence of engineering and new technology to provide superior build and optical quality. This lens has a large aperture of f/2.8 throughout the entire zoom range, a minimum focusing distance of 28cm (11") and a maximum magnification of 1:5. Specially designed to suit the characteristics of digital SLR cameras, this lens provides a high level of optical performance. Its design incorporates both glass-mold and hybrid aspherical lens technology, which offers superior peripheral brightness, extremely high image quality as well as compact and lightweight construction. Special Low Dispersion (SLD) and Extraordinary Low Dispersion (ELD) glass elements provide excellent correction of color aberrations. The super multi-layer lens coating reduces flare and ghosting, a common problem with digital cameras. High image quality is assured throughout the entire zoom range. 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. DC lenses are exclusively designed for digital SLR cameras. The image circle (rear of lens) is made 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.

EX lens series denotes excellence of engineering and new technology.

Large aperture of f/2.8 throughout the entire zoom range.

Correction for various types of aberration provided by one SLD (Special Low Dispersion) glass element and two aspherical lenses.

Super Multi Layer (SML) coating reduces flare and ghosting from which digital cameras tend to suffer.