Ambient light sensor
On PCs that are equipped with an integrated Ambient Light Sensor (ALS), Windows’s Adaptive Brightness Feature will automatically calculate the optimal brightness level based on the brightness slider setting and current ambient lighting.
Users have the option to turn off automatic brightness adjustment from PC Settings, on the General page. Figure 1 User interface control for ALS-based automatic brightness adjustments shows the corresponding steps and user interfaces.
Figure 1 User interface control for ALS-based automatic brightness adjustments