The Sigma MC-21 Mount Converter (Canon EF to L-Mount) allows Canon EF mount lenses to be used on L-mount mirrorless cameras from Sigma, Leica, and Panasonic with autofocus support. It retains full electronic communication including phase-detection AF, OSS, and EXIF data transmission. The MC-21 is part of Sigma's L-mount adapter family.
Product released: May 16, 2019
Latest firmware version
Version 1.4, released December 22, 2022
Verified by LatestUpdate: June 18, 2026
What's new in version 1.4
・MF assist is now supported when a SIGMA CINE LENS for Canon EF mount is attached.・It makes the converter compatible with the SIGMA CINE LENS FF High Speed Prime Line 65mm T1.5 FF for Canon EF mount.*When using the SIGMA FF High Speed Prime Line 65mm T1.5 FF for Canon EF mount, be sure to update the firmware of the SIGMA MOUNT CONVERTER MC-21 EF-L to Ver. 1.4.
What is the Sigma Mount Converter MC-21 (EF to L-Mount)?
The Sigma MC-21 Mount Converter (Canon EF to L-Mount) allows Canon EF mount lenses to be used on L-mount mirrorless cameras from Sigma, Leica, and Panasonic with autofocus support. It retains full electronic communication including phase-detection AF, OSS, and EXIF data transmission. The MC-21 is part of Sigma's L-mount adapter family. It was originally released on May 16, 2019.
What is the latest firmware version for the Sigma Mount Converter MC-21 (EF to L-Mount)?
The latest firmware version for the Sigma Mount Converter MC-21 (EF to L-Mount) is 1.4. It was released on December 22, 2022.
What changed in Sigma Mount Converter MC-21 (EF to L-Mount) firmware version 1.4?
Sigma Mount Converter MC-21 (EF to L-Mount) firmware version 1.4 includes the following changes: ・MF assist is now supported when a SIGMA CINE LENS for Canon EF mount is attached.・It makes the converter compatible with the SIGMA CINE LENS FF High Speed Prime Line 65mm T1.5 FF for Canon EF mount.*When using the SIGMA FF High Speed Prime Line 65mm T1.5 FF for Canon EF mount, be sure to update the firmware of the SIGMA MOUNT CONVERTER MC-21 EF-L to Ver. 1.4.
How do I update the Sigma Mount Converter MC-21 (EF to L-Mount) firmware?
To update the Sigma Mount Converter MC-21 (EF to L-Mount) firmware, download the latest version (1.4) from Sigma's website. Follow Sigma's installation instructions, which typically involve copying the firmware file to a memory card or connecting via USB. You can download the latest firmware from Sigma's support page.
Where can I download the latest Sigma Mount Converter MC-21 (EF to L-Mount) firmware?
Details and download instructions for the latest Sigma Mount Converter MC-21 (EF to L-Mount) firmware (version 1.4) are on Sigma's official release page: https://www.sigma-global.com/en/support/firmware/mc-21/?mount=ef-l
How do I check for Sigma Mount Converter MC-21 (EF to L-Mount) firmware updates?
You can track Sigma Mount Converter MC-21 (EF to L-Mount) firmware updates automatically on LatestUpdate.io. We monitor Sigma's releases and notify you when new firmware versions are available, so you never miss an update.
How often does Sigma release firmware updates for the Sigma Mount Converter MC-21 (EF to L-Mount)?
We have tracked 4 firmware versions for the Sigma Mount Converter MC-21 (EF to L-Mount). Sigma releases updates to fix bugs, improve performance, and add new features. Track this product on LatestUpdate.io to be notified of future releases.
Who makes the Sigma Mount Converter MC-21 (EF to L-Mount)?
The Sigma Mount Converter MC-21 (EF to L-Mount) is manufactured by Sigma. Visit the official product page for more information.