Sigma has introduced new versions of two of its macro zoom lenses that are compatible with all Nikon digital SLRs. The 17-70mm F2.8-4.5 DC Macro HSM and 18-50mm F2.8 EX DC Macro HSM are identical to two existing Sigma lenses, with the addition of a built-in hypersonic motor (HSM). HSM makes the lenses fully compatible with Nikon cameras that do not use body-driven autofocus motors, such as the D40 and D40x digital SLRs. The lenses are designed to be used with those cameras and other models that use APS-C-size sensors. The 17-70mm lens incorporates a Special Low Dispersion element and an aspherical element to minimize optical distortions. It offers a 79.7-22.9-degree angle of view (equivalent to a 25.5-105mm lens on a 35mm camera) and a minimum focusing distance of 7.9 inches. Its maximum magnification is 1:2.3. The 17.3-ounce lens takes a 72mm filter.

The 18-50mm incorporates Special Low Dispersion, Extraordinary Low Dispersion, and aspherical elements, as well as Sigma’s Super Multi Layer Coating for reducing flare and ghosting. It provides a 76.5-31.7-degree angle of view (equivalent to a 27-75mm lens on a 35mm camera) and a minimum focusing distance of 7.9 inches. Its maximum magnification is 1:3. The 18.9-ounce lens takes a 72mm filter.

The MSRP price of 17-70mm F2.8-4.5 DC Macro HSM lens is $590.

Website :  Sigma Introduces Macro Lenses for Nikon Cameras