Light Meter Plus от 88b Coffee

Light Meter (RGB & Luminance) extension enables you to measure the environment's light and luminance level with your computer's camera!

This add-on helps you easily measure some important light metrics, such as the RGB value and luminance level. When you open the app for the first time, it may ask you about camera access. Please accept the dialog box to start the add-on. Also, note that the app may take a few seconds before get ready. So please be patient while the add-on is loading. Once the loader is disappeared, the app is ready to use. It uses the camera in your system to capture the surrounding light. If your computer does not have a camera, please attach one to it before using the add-on. On the top toolbar within the interface, you see several pieces of information about the captured light. You can also change the RGB calculation precision via the slider at the bottom.

Note: The interface for this app can be opened in a separate window, new tab, or toolbar popup (choose a context from the toolbar button's right-click menu). When you open the app for the first time, please open it in the window or tab to see the camera permission dialog.

If you see any bug or have a feature request, please fill out the bug report form on the addon's homepage (https://mybrowseraddon.com/light-meter.html).