Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 222)

FAQ
Are there any restrictions on the image quality?
All single exposures and the multiple-exposure image are captured at your specified
image quality.
Can I merge images recorded on the card?
With [ Select image for multi. expo. ], you can select the first single exposure from the
images recorded on the card ( ). Note that you cannot merge multiple images already
recorded on the card.
How are multiple-exposure files numbered?
With the camera set to save all images, multiple-exposure image files are named with
the next number after the number of the last single exposure used to create them.
Will auto power off take effect during multiple-exposure shooting?
During multiple-exposure shooting, auto power off will not take effect. Note that before
you start multiple-exposure shooting, auto power off automatically takes effect at the
time set in [ :
Auto power off ], which will cancel multiple-exposure shooting.
222