If you're looking to master color correction, you need to understand how to read a waveform monitor and vectorscope. While this may seem like a daunting task, it's actually pretty straightforward once you get the hang of it! Here are some of the basics that can help you learn how to read these tools:
The saturation of a color is the intensity of it. It's also sometimes called "how gray" or "how white." When there's more gray in a color, you have low saturation; when there's more white, you have high saturation; when there's more black, you have even higher saturation.
The difference between saturated and desaturated hues can be subtle: if you compare 100% saturated blue to 50% saturated blue in isolation (i.e., without any context), they look quite different—but when placed next to each other they're not so much different at all!
The same concept applies for lower saturations as well: if we compare 100% desaturated red with 0% desaturated red by itself, those two colors look different—but when placed next to one another on screen (with other colors around them), the difference is again less pronounced than it might seem initially.
For the purposes of this explanation, let's imagine an image that has a 100% black background and a 100% white object on top. When you play back this frame in real time, your monitor will only show you a constant shade of gray. This is because the signal from your camera is too complex for your computer to interpret it all at once; there are millions of colors in each pixel, which we can't perceive until they're broken down into RGB colorspace by our monitors.
That said, when we look at Luma levels (the brightness) on our waveform monitor or vectorscope (more on those later), they'll show us both how much white there is and how much black there is in every single frame. Luma readings are measured in percentages—and they'll tell us if we've got enough contrast between bright objects and dark backgrounds!
A waveform monitor can help you see the chroma levels. The vectorscope can help you see the chroma levels, too.
The waveform monitor and vectorscope are tools that show different parts of an image on screen at the same time. You can use both to check your video signal as it's being recorded, edited or played back using a computer.
When you first look at an image and all three colors are perfect, then you have a good image. However, if just one color is perfect but the other two are not, then you have a good image. Finally, if all three colors are not perfect, then you have a bad image.
If you have one color that is correct but the other two are not, it's probably an error. If you have two right colors and one wrong one, it could be a problem with either of those two colors, or with both. If all three colors look correct, then you’re good!
The best way to determine if your waveform monitor is set up properly is by comparing what's happening in your program with the vectorscope readings. If the vectorscope appears normal and the waveforms don't match up at all, there’s probably something wrong with your video signal or monitor setup.
It's important to understand that reference colors are not just any old colors. They must come from a known good source, or they will not be able to be used as a reference color. You can find some of these sources on the Internet by doing a simple search for "reference colors." However, please note that it is always better to use a set of references that comes from your own sources.
If you find yourself in an environment where all of these conditions cannot be met, then don't worry about it! A waveform monitor and vectorscope should never be used as an absolute deciding factor when choosing which camera settings work best for your project; instead, use them as tools for understanding how light behaves when projected through different lenses onto different surfaces (which is called "color temperature").
Now you know how to read a waveform monitor and vectorscope, but the most important thing is that you practice! You’ll get better and faster at reading these charts with time, so keep practicing.