Canon EOS R3 Advanced User's Manual page 697

Transferring Multiple Images at Once
Selecting images to transfer
Selecting multiple images
Transferring RAW+JPEG or RAW+HEIF images
After shooting, you can select multiple images and transfer them all at once, or you can
transfer unsent images or images that could not be sent previously.
You can continue shooting still photos as usual during transfer.
Caution
Image transfer in progress is paused while the still photo shooting/movie recording
switch is set to <
If you will transfer many images, consider using a household power outlet
accessory (sold separately).
Selecting images to transfer
1.
Select [
2.
Select [Image sel./transfer].
>. To resume image transfer, set it to <
: Image transfer].
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