Canon EOS-1D X Mark III Advanced User's Manual page 478

3.
Set the desired processing conditions.
Use shot settings
Images are processed using image settings at the time of capture.
RAW images captured in HDR shooting are processed to create HEIF
images, and other RAW images are processed to create JPEGs.
Set up processing→JPEG/Set up processing→HEIF
Turn the <
Turn the <
Press <
To return to the image settings at the time of shooting, press the <
button.
Comparison screen
You can switch between the [After change] and [Shot settings]
screens by pressing the <
Items in orange on the [After change] screen have been modified
since the time of capture.
Press the <
> dial to select an item.
> or < > dial to switch the setting.
> to access the function setting screen.
> button.
478
> button and turning the <
>
> dial.