Procedure to downgrade firmware on the 5D3 from 1.2.3 to 1.1.3 ?

[rustmonster]

Currently have the latest working nightly build working on my 5D MKIII running on 1.2.3 as I needed a clean HDMI signal for a job.

Now looking to downgrade back to 1.1.3 as that seems to be the most stable option with more regular updates.

I searched for the best practices to downgrade and the majority of posts were about getting down from 1.3.3 so they could install, Not going from 1.2.3 to 1.1.3.

I'm wondering what the best steps and order to take to ensure I don't brick or damage my camera. Should I remove Magic Lantern from the camera, then downgrade the firmware, then re install Magic Lantern? Or can I downgrade the firmware immediately and then overwrite the 1.2.3 firmware on the SD card with one of the latest 1.1.3 nightly builds?

[Lars Steenhoff]

- with canon utility downgrade to the older canon firmware
- install the matching magic lantern on the sd card and fire the camera up

This is all it took for me to downgrade

Don't know if it would be better to uninstall first.

[Walter Schulz]

You can use in-cam firmware upgrade option to downgrade to 1.1.3. The only version (at time of writing) denying in-cam firmware downgrade is 1.3.3.

[HondaATC]

Just wanted to reply and say - I also successfully downgraded from 1.2.3 by copying the  1.1.3 Firmware to my CF file and just running the in-camera firmware update. I got the file from here: http://pel.hu/eoscard/

For anyone else researching / going through the same process, it was about as painless as it could be