When a BrightSign with Carousel boots up, the display resolution is set to the Carousel channel resolution it is provided. These are all the resolutions that Carousel for BrightSign supports, regardless of what BrightSign documentation may list. Note that to display a UHD channel your BrightSign model must support it, see BrightSign Model Compatibility for Carousel 7 for the currently supported 4K compatible players.
Supported Resolutions - 60p only
3840x2160
1920x1200
1920x1080
1680x1050
1600x1200
1440x900
1400x1050
1360x768
1280x1024
1280x960
1280x800
1280x768
1280x720
1024x768
800x600
720x576
720x480