How do I adjust a stream’s brightness filter from the command line?

Use videoFilter=brightness with the intended stream output. Display-wide softwareBrightness and filter... commands adjust the display through separate features. To adjust the stream’s own brightness filter, use videoFilter.

For an already configured display stream, replace Desk Display with its source display name and select the stream configuration ID:

betterdisplaycli get -name="Desk Display" -stream -specifier=1 -videoFilter=brightness
betterdisplaycli set -name="Desk Display" -stream -specifier=1 -videoFilter=brightness -value=0.005

The numeric input allows finer adjustments than a whole-percentage slider step. Values use the filter’s numeric range. 0.005 is a numeric value, not a request for 0.005 nits. Query the supported limits with get and -min or -max when needed.

Individual video-filter commands require Pro. The stream or capture output must also be available on your Mac and have any required capture permissions.

Setting the filter value does not start the stream or enable built-in filter processing. Configure the stream and enable its video filters separately. Use exactly one output type: stream, pip, videoFilterWindow or contentStreamWindow. The app-wide selected-content window does not need a display selector.

See CLI setup, stream-filter recipes and the command reference for other outputs, filter names and batch adjustments. Editing preference files is not a replacement for a supported live command.