The Sigma Mount Converter Mc-21 allows Sigma Sa mount mount interchangeable lens owners to use their lens investment on L-Mount camera bodies. The converter allows more freedom of choice for L-Mount cameras from Sigma, Leica Camera and Panasonic, enhancing the extensibility of the L-Mount system. Effective use of lens investment Attaching the Mc-21 to your collection of Sigma Sa mount and Sigma's Canon Ef mount compatible lenses allows them to be used as L-Mount system lenses, promoting the effective use of valuable lenses already owned. 29 interchangeable lenses available to be used for L-Mount cameras The Mc-21 increases the number of interchangeable lenses manufactured by Sigma that can be used with the L-Mount system by 29 lenses. Compatible with the autocrop function, mounting Aps-c size image circle Dc lenses to a camera body equipped with a 35mm full size sensor still allows immediate use for shooting. 12-24mm F4 Dg Hsm | Art 14-24mm F2.