The MC-21 Mount Converter enables the use of Sigma EF-mount lenses on L-mount mirrorless camera bodies, and maintains full lens performance, including autofocus in AF-S mode and auto-exposure, as well as in-camera correction and image stabilization technologies. An integrated LED can be used to display select Sigma lens compatibility with the adapted camera body, and the adapter also has pre-loaded lens data to support peripheral illumination, chromatic aberration, and distortion corrective functions. In order to maintain a high degree of image quality, the interior of the adapter is flocked to reduce reflections, and it also retains full EXIF data to benefit post-production and file management. Additionally, a removable tripod mount is included for more stable mounting when working with heavier lenses.

Per Sigma, this Mount Converter/Lens Adapter is compatible with a select number of Sigma's own EF-mount lenses, and may or may not be suitable for use with other manufacturers' EF-mount lenses.

Compatibility
Cameras
Panasonic S1R
Panasonic S1

Lenses
12-24mm f/4 DG HSM Art
14-24mm f/2.8 DG HSM Art
24-35mm f/2 DG HSM Art
24-70mm f/2.8 DG OS HSM Art
24-105mm f/4 DG OS HSM Art
60-600mm f/4.5-6.3 DG OS HSM Sports
70-200mm f/2.8 DG OS HSM Sports
100-400mm f/5-6.3 DG OS HSM Contemporary
120-300mm f/2.8 DG OS HSM Sports
150-600mm f/5-6.3 DG OS HSM Sports
150-600mm f/5-6.3 DG OS HSM Contemporary
14mm f/1.8 DG HSM Art
20mm f/1.4 DG HSM Art
24mm f/1.4 DG HSM Art
28mm f/1.4 DG HSM Art
35mm f/1.4 DG HSM Art
40mm f/1.4 DG HSM Art
50mm f/1.4 DG HSM Art
70mm f/2.8 DG Macro Art
85mm f/1.4 DG HSM Art
105mm f/1.4 DG HSM Art
135mm f/1.8 DG HSM Art
500mm f/4 DG OS HSM Sports
17-70mm f/2.8-4 DC Macro OS HSM Contemporary
18-35mm f/1.8 DC HSM Art
18-200mm f/3.5-6.3 DC Macro OS HSM Contemporary
18-300mm f/3.5-6.3 DC Macro OS HSM Contemporary
50-100mm f/1.8 DC HSM Art
30mm f/1.4 DC HSM Art