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.