At Bri’s request, I’m writing this quick primer that will help you get started with basic colour correction.
A few starting points:
- Yes, I’m calling it “colour” throughout this column. I’m Canadian, that’s the way it’s spelt here.
- This is not meant to be a comprehensive study of colour correction, it’s just enough to get you started. It’s a deep rabbit hole to dive into if you so choose.
This walkthrough will be using a clip from a music video I shot a few years ago. Here’s a sample of the raw footage:
I chose this clip because the wall in the background was white in the studio we shot in. Knowing that will guide us through the colour correction process. Once we get the wall to look white, everything else (like skin tone) should look “normal”.
Some starter points about colour theory:
- All shots are composed of three basic colours at varying intensities: Red, Green and Blue, hence the common acronym RGB.
- White is 100% Red, 100% Green and 100% Blue. This may seem counterintuitive until you consider the next point:
- Black is 0% Red, 0% Green and 0% Blue.
The first thing to do is find the RGB Parade Video Scope in your editing program. You can’t really do proper colour correction without this valuable tool. The two axes of the scope are described here:
The horizontal axis of the scope is just the horizontal axis of your shot. Watch the scope as you play your clip and you’ll sort of see how that works. The vertical axis is intensity; in the digital world, 255 represents 100%.
Knowing that, I can now interpret the scope to see that the background wall on the left of the clip is represented by the three circled areas here:
The scope allows me to see two things right away:
- The “white” has a little too much Green and not quite enough Blue. Remember for white, the three colour components should be equal.
- The wall isn’t actually showing as white because the intensity level is well below 100%; it’s more a dull grey.
To solve the first problem, I’ll use a Colour Balance plugin. There are more sophisticated tools to do this job, but I’m keeping it simple for this walkthrough.
This has evened out the three colours as desired.
To solve the second problem I’ll use a Brightness and Contrast plugin. Watch the RGB Parade Scope as you change the values here - you’ll see immediately that this plugin is doing something quite simple, in terms of colour theory. I’ll adjust the values until the colours span all the way from 0% to 100%:
That’s it! Here’s the resulting processed clip. You can see that the skin tone looks realistic and the colours “pop” more.
I typically do this kind of work looking only at the RGB Parade Scope; I don’t even refer to the clip itself until the end, just to double-check what I’ve done.
If there’s nothing in your shot that’s white, you can always put something white (like a sheet of paper) in front of the camera during slate and use that to colour correct the rest of the clip.
One last tip for the shooting process: learn how to white balance your camera, and do it every time you change the lighting of your shot. This will result in clips that need less drastic correction during post.
I wrote this column up pretty quickly, so please let me know if you have any questions about anything I might have missed.