Canon EOS 6D Mark II Function Instruction Manual page 54

Sending Images to a Smartphone from the Camera
If necessary, also read "NFC Function Cautions" (p.29).

During the image transfer operation, a picture cannot be taken even if

the camera's shutter button is pressed.
Images cannot be sent using the NFC function while the camera is

connected to another device via Wi-Fi. In addition, the camera cannot be
connected to multiple smartphones via Wi-Fi at the same time.
Even if MOV-format movies are displayed in the list, they cannot be

saved to a smartphone.
You can cancel the image transfer by selecting [Cancel] during the

transfer.
You can select up to 999 files at a time.

With a Wi-Fi connection established, disabling the smartphone's power

saving function is recommended.
When using the NFC function while playing back an image, device

registration will not be performed.
When you reduce the image size, all images to be sent at the same time

are resized. Note that movies and b size still photos are not reduced.
When you use a battery to power the camera, make sure it is fully

charged.
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