Contemporary Series: The new SIGMA 16mm F1.4 DC DN | Contemporary is the world�s first interchangeable lens for mirrorless cameras in the APS-C format to offer a 24mm focal length (35mm equivalent) and F1.4 brightness. Compact Design: Developed to feature a lightweight, compact package for everyday use, SIGMA DN lenses for mirrorless cameras deliver superior performance covering the key focal lengths. Lens Structure: The 16mm F1.4 DC DN | Contemporary features a lens structure with 16 elements in 13 groups and includes the finest materials. Special Design: The special design of the focus lens group allows fast and smooth AF performance for videography and more Stepping Motor: The optical design and stepping motor deliver smooth autofocus during video shooting