The SIGMA 70mm f2.8 DG MACRO Art lens is designed to put optical performance in the foreground and thus meet the demanding image quality requirements that define the Art line of products. For this reason, the inner focusing was dispensed with. The 70mm lens delivers an impressive resolution and unbelievable clarity for the medium telephoto range, which go well beyond the expectations of a macro lens. The ironless DC motor further improves image quality, while an optimized algorithm ensures exceptionally smooth autofocus performance from a heavier, high-performance lens. In order to achieve maximum performance at every shooting distance, the lens has an extending, two-group floating focus mechanism. The focus-by-wire system prevents the direct mechanical connection between the focus ring and focus drive.