The built-in display brightness of your Macbook or iMac is synchronized to the external monitor.
Custom brightness and contrast values are computed for each external monitor by passing the built-in brightness through a curve algorithm that is completely configurable by the user.
The brightness and contrast is adjusted automatically throughout the day, by using the sunrise, noon and sunset times for your location.
The adaptive algorithm is disabled and the external monitor can be controlled by hotkeys or the Lunar UI.
Custom hotkeys can be set for brightness, contrast and volume and the brightness and volume keys on the Apple keyboard work out of the box.
An external light sensor reads the ambient light periodically and sends it to Lunar for computing brightness and contrast values for each external monitor.
Lunar actually controls the hardware brightness and contrast of the monitor and doesn't use a software dark overlay.
By implementing the DDC standard Lunar supports all modern monitors as long as they are connected through a compliant cable.
Lunar works very well in combination with macOS Night Shift and True Tone features, because there's no software image processing that could interfere with them.
If the monitor is used as the audio output, volume keys will change the monitor volume as expected.
Special support for Apple-vendored monitors is included for smoother transitions, extended brightness range and use of native APIs. The monitors supporting this include LG UltraFine, LED Cinema and Thunderbolt displays.
Every important action has a configurable keyboard shortcut. Set all monitors to 25% of their brightness range, mute the monitor audio or pause Lunar's adaptive algorithm with a single key press.