The Sigma 105mm f/2.8 EX DG OS HSM Macro is a short-telephoto prime characterized by its ability to achieve a 1:1, life-size magnification along with a 1' minimum focusing distance for macro applicati espandi...ons. The optical design employs two SLD elements to virtually eliminate chromatic aberrations and color fringing throughout the focusing range for improved clarity and color rendering. A Super Multi-Layer Coating has also been applied for greater contrast when working in strong lighting conditions.