The Sigma MC-21 Mount Converter allows Sigma's SA-mount lenses to be used on L-mount cameras, such as the Panasonic S1/S1R.
Auto-exposure and high precision AF in AF-S mode is achieved (not compatible with AF-C).
The MC-21 has a built-in tripod socket and LED that lets users know if the mounted lens is compatible or not, and when a lens firmware update is available.