MajorGeeks published a tutorial about adaptive brightness in Windows 10.

How to Enable or Disable Adaptive Brightness in Windows 10

Most laptops and tablets may utilize ambient light sensors to detect surrounding levels of light, and the Adaptive Brightness feature in Windows can detect changes in ambient light and automatically adjust the display brightness as needed to match surrounding lighting conditions. Sometimes, this makes your display dark, and you might want to enable or disable Adaptive Brightness.

How to Enable or Disable Adaptive Brightness in Windows 10 - MajorGeeks