Firmware update for EF to RF(EOS R) Speed Booster ULTRA (Windows)

Firmware upgrade for Canon EF - RF(EOS R) T Speed Booster ULTRA®

 

RELEVANT PRODUCTS

This information is for the following models:

  • Canon EF to RF (EOS R) T Speed Booster® ULTRA 0.71x (MB_SPEF-EFR-BT1)

  • Canon EF to RF (EOS R) T Speed Booster® ULTRA 0.71x CINE (MB_SPEF-EFR-BT2)

Disclaimer: these release notes only highlights significant changes to the firmware. There may have been other changes that are not documented.

 

ABOUT THIS DOWNLOAD

 

  • Name: Firmware update V2.60 (#2361) for Canon EF to RF (EOS R) T Speed Booster® ULTRA
  • Release date:  05 May 2026
  • Benefits and improvements: 
    • To reduce download size, EF-RF (EOS R) firmware from 2021 or older is no longer available for downgrade.
    • Fixed stability issue with manual lens EXIF function a.k.a. 'chip' emulation.

 

 

FIRMWARE HISTORY: 

  • More firmware history can be viewed in the archive: here

 

 

 

SYSTEM REQUIREMENTS:

Operating Systems

The latest version of the firmware update is compatible with most commonly-used versions of Microsoft Windows:

  • Windows® 10 1809 or newer (64-bit)
  • Windows® 11
  • Windows® 11 on Arm

A micro-USB cable is required to connect the Smart AdapterTM or Speed Booster® to the computer.

While performing the firmware update, don't disconnect the USB cable, otherwise, the adapter may become inoperable due to sudden disconnection. In most cases, an adapter made inoperable by an interrupted firmware update can be fixed by performing the firmware update again.

Don't connect the adapter to any camara or lens while performing the firmware update.