Class is in session! The topic: waveform monitors.
Waveform monitors can be extremely helpful tools for getting the correct exposure on an image, but they do take a little know-how in order to use them correctly. In this helpful tutorial from Aputure, you get to learn what a waveform monitor is, how to use one, and how it differs from other tools when it comes to measuring exposure.
If you're having a difficult time understanding what exactly a waveform monitor is, the video describes it as "a graph that charts the brightness values of a picture from left to right." The standard unit of measurement for brightness values is IRE, which goes from 0 (complete blackness) to 100 (complete white), so checking your X and Y values on your scope can tell you whether you're correctly (evenly) exposing your image without having to rely on your monitor, which may or may not be accurate.
Now that you know the basics of waveforms, it would be incredibly beneficial to start practicing reading them. When it comes to making films, exposure is supremely important, and waveforms are another tool you can use to ensure that you're getting the shot you want.