Canon EOS R6 Mark II Mirrorless Camera with 24-105mm f/4-7.1 Lens - Manual (Page 923)

HDMI Resolution
Set the image output resolution used when the camera is connected to a television or
external recording device with an HDMI cable.
1.
Select [ : HDMI resolution].
2.
Select an option.
Auto
The images will automatically be displayed at the optimum resolution
matching the connected television.
1080p
Output at 1080p resolution. Select if you prefer to avoid display or
delay issues when the camera switches resolution.
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