Canon EOS-1D X Mark III Advanced User's Manual page 628

Using EOS Utility
For EOS Utility instructions, refer to the EOS Utility Instruction Manual. Remote shooting is
only one of the many camera operations available.
Caution
Some menu items are not available when the camera is connected to a network.
In remote shooting, the AF speed may become slower.
Depending on the communication status, image display or shutter release timing
may be delayed.
In Remote Live View shooting, the rate of image transmission is slower compared
to a connection via an interface cable. Therefore, moving subjects cannot be
displayed smoothly.
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