From SIGMA:
This firmware update makes the SIGMA MOUNT CONVERTER MC-11 EF-E compatible with the latest SIGMA interchangeable lenses firmware. For customers who own the SIGMA MOUNT CONVERTER MC-11 EF-E, please update the firmware via SIGMA Optimization Pro* by connecting it to a computer using the supplied USB Cable.
*Before updating the SIGMA MOUNT CONVERTER MC-11 firmware, please ensure SIGMA Optimization Pro has been updated to ver. 1.4.1 or later for Windows, and ver. 1.4.0 or later for Macintosh.
Applicable product
Benefits of the update