Canon EOS-1D X Mark III Advanced User's Manual page 886

Using a Card Reader
You can use a card reader to import images to a computer.
1.
Install Digital Photo Professional (
2.
Insert the card into the card reader.
3.
Use Digital Photo Professional to import the images.
Note
When downloading images from the camera to a computer with a card reader
without using EOS software, copy the DCIM folder on the card to the computer.
Refer to the Digital Photo Professional Instruction Manual.
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