Sigma's 70-300mm f4-5.6 APO DG Macro is one of several tele zoom lenses. It is a compact Apochromatic tele zoom lens incorporating two Special Low Dispersion glass elements in the front lens group, plus one Special Low Dispersion glass element in the rear lens group, to minimize chromatic aberration. This Tele-Macro Zoom lens is capable of focusing down to 1:2 (half life-size) reproduction ratio at 300mm focal length with superb optical quality. It also has a switch for changeover to macro photography at focal lengths between 200mm and 300mm.