Features:

• A minimum focusing distance of 20cm (7.9"), a maximum magnification of 1:3
• Large aperture of F2.8 throughout the entire zoom range
• 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
• Reduced Ghosting and Flare The super multi-layer lens coating reduces flare and ghost. High image quality is assured throughout the entire zoom range

Editor Reviews:

Product Description:
Large aperture zoom lens designed specially for use with digital SLR cameras with a minimum focusing distance of 20cm (7.9"). This lens 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.

Amazon.com Product Description:
Sigma's 18-50mm EX series macro lens is specially designed for Nikon digital SLR cameras with a minimum focusing distance of 20 cm (7.9 inches), making it suitable for a wide variety of subjects. The lens offers a large aperture of F2.8 throughout the entire zoom range, along with a maximum magnification of 1:3 for close-up macro photography. The interior, meanwhile, incorporates both glass-mold and hybrid aspherical lens technology to deliver superior peripheral brightness and extremely high image quality. Add in Special Low Dispersion (SLD) and Extraordinary Low Dispersion (ESD) glass elements and you have a lens that can correct all types of color aberrations while providing a high level of optical performance at every interval.

The lens also offers a super multilayer lens coating that reduces flare and ghosting, a common problem among many digital cameras. Users will also appreciate the inner focusing system, which provides a fast autofocus speed while preventing the front of the lens from rotating, making it particularly suitable for use with circular polarizing filters and the petal-shaped lens hood (included). The Sigma 18-50mm lens--which measures 3.1 inches in diameter and 3.4 inches long--weighs only 15.9 ounces and carries a one-year warranty.

Rating : - ..not great

I really wanted to buy this lens. Unfortunately, my kit lens (Nikon 18-55 EDII) is a lot sharper than this!! I tried this previously at a local trade show. Although the build quality seems very good. It appears very soft at f/2.8 across its entire zoom range. That in itself was a deal breaker for me. The whole idea of having a lens like this is low light performance and some respectable sharpness. Sharpness does not come close to respectable for my taste. I was told that there are sample to sample variations on Sigma lenses and not to mention some focus issues. Looking for an acceptable sample is like picking straws!! I decided not to go thru this hassle. So for everyone else, test your sample carefully before making your purchase if you really want this.