Sigma MOUNT CONVERTER MC-11 (EF-E) firmware v1.11

Sigma · Released Sep 8, 2017 · First seen Jul 5, 2026

v1.11 is not the latest firmware for the Sigma MOUNT CONVERTER MC-11 (EF-E): the current version is v1.43 (August 27, 2026). Go to v1.43

In short — summary by updatemystuff.com

Fixes false autofocus confirmation on Sony a9 with certain zoom lenses in telephoto mode; adds compatibility with two Canon-mount lenses.

  • Fixed false autofocus confirmation on Sony a9 with certain zoom lenses in telephoto mode
  • Added compatibility with 24-70mm F2.8 DG OS HSM Art for Canon
  • Added compatibility with 100-400mm F5-6.3 DG OS HSM Contemporary for Canon

Written from Sigma's release notes, which are printed in full below.

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What's in this update

It has corrected the phenomenon whi​ch may occur with the combination of SIGMA MOUNT CONVERTER MC-11 and some of SIGMA’s interchangeable zoom lenses on Sony a9 (ILCE-9) that when using AF-S mode and shooting in telephoto range, it could occasionally display the shot as in focus, although it may not be correctly locked on the subject.

It has become compatible with the SIGMA 24-70mm F2.8 DG OS HSM | Art for CANON​ (Firmware Ver.1.02), as well as the SIGMA 100-400mm F5-6.3 DG OS HSM | Contemporary for CANON (Firmware Ver1.03).

Note: Before updating the 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.

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Other versions for this product

See the full firmware history for the MOUNT CONVERTER MC-11 (EF-E)