If you have a Canon 5D Mark III don’t upgrade the firmware to 1.3.6. I did. Canon has changed their firmware such that it is really difficult to downgrade, when it used to be simple. I was running 1.3.5 and upgraded last evening. Then, I wanted to reload Magic Lantern to play with recording 4K RAW videos. That’s when I ran into the issue. Evidently, Canon wants everyone to buy the new EOS R5 for full 4K (R6 has 8K, but it’s also $3900, body only) video support, which strangely isn’t available on the 5D Mark IV, it only has cropped 4K, not full. Switching to the new EOS R line has its drawbacks, the main one being Canon created a new RF mount, which means either using a EF-to-RF converter or buying all new glass. The really smart guys behind the development of Magic Lantern gave my 5D Mark III new life. Canon has released 1.3.6 firmware to prevent downgrades so that people cannot use Magic Lantern because it would cannibalize future sales of the EOS R line when people realize that the 5D line can record 4K video already. I’m not worried about voiding the warranty because I bought it in 2012 and it’s been out of warranty for years. However, I will be shooting 4K video with it because, well, as I said earlier, Canon made it really difficult to downgrade. I still was able to downgrade it. Now, I’m running Magic Lantern.
If you have upgraded to 1.3.6, this video will show you how to downgrade.
Cheers!
