The Auto Adjust Video Based on Lighting feature in Windows 10 v1809 is designed to improve the visibility of a video when present in a bright environment. The automatic setting makes sure your screen is readable no matter where you go.

Microsoft says that that Adjust video based on lighting works like the auto-brightness control present in mobile phones. It uses the light sensor present in your device to detect ambient light and determine the intensity of the surrounding light. When done, the sensor automatically adjusts video brightness to the desired level.

You can check if your PC is equipped with the light sensor. Most PCs these days do! For checking this, open ‘Settings’ > Choose ‘System’ > ‘Display Settings’.

If you have the option to turn on Auto-brightness, you most likely have a light sensor.

Next, launch ‘Device Manager’ and see if you can find ‘Light Sensor’ as an entry under ‘Sensors’. If you do, your PC is equipped with a light sensor.

Enable Auto Adjust video based on lighting

Open Settings and choose the Apps icon. Select Video playback from the left pane and turn on ‘Adjust video based on lighting‘.

Once done, close the setting and exit. Even if you use it, you can still move the Change brightness slider to fine-tune the brightness level as per your preference.

Windows HD Color settings

Apart from the above, there’s a new Windows HD Color settings page available under Settings > System > Display. It specifies if your hardware is compatible with

High Dynamic Range (HDR)
Wide Color Gamut (WCG) content

These features are enabled for higher-end 4K displays. It also displays you HDR content, such as photos, videos, games on your PC.