The Sigma 100-400mm F5-6.3 DG DN OS Contemporary is a full-frame telephoto zoom for mirrorless L-Mount featuring 21 elements in 15 groups, Optical Stabilizer, and a compact mirrorless-optimized design. It uses a stepping motor for autofocus and covers 150-600mm full-frame equivalent range from APS-C cameras. The lens belongs to Sigma's Global Vision Contemporary line.