Adjusting color channels using RGB Color Corrector and RGB Curves effects

There are two basic approaches to adjusting colorcast: either change the values within each individual color channel or use a color wheel to adjust all the color channels at once. Either method works well. In this movie I'll show you the two effects that work on the color-channel-by- channel basis: RGB Color Corrector and RGB Curves. I'll give you a basic sense of how they work. I'll give you more specific details on working with the particular circumstances in the movie entitled "Fixing color cast, skin tone, and other color issues." Let's start with the RGB Color Corrector.

I'll turn it on, and I've already apply some tonality fixes to this, because when you do color correction you do tonality first and then do your color effects. Let me open it up and give you a sense of what it looks like. At the top here there is a little dropdown menu. It says Composite, Luma, Mask and Tonal Range. I'll explain Mask and Tonal Range in my secondary color correction chapters. Basically, this allows you to define an area in the clip that you want to use as a mask and limit your work to that, and Tonal Range says that you can change what you define as a midtone, highlight, or shadow.

Luma, if I click that, that changes this to a grayscale image and if you look at the Waveform monitor down here, if I change it to grayscale, by golly, it shouldn't change, because this is showing only luma nothing to do with color. Let's check and see if Premiere Pro is working correctly, and lo and behold it did not move an iota, which is a good thing. Let's go back to Composite. This little box here says Show Split view. This gives you a kind of a before and after. If I click that, let's say make a dramatic change to a color or something like that, we'll just raise red way like up there, and you can see, oh there is the before.

There is the after. So you can get a view as you work along, if that's the way you like to work. Turn that guy off. And you can change the view from Horizontal to Vertical and change which percentage is going to be the before and which is going to be the after. The Tonal Range definition here is part of that Secondary color correction thing I mentioned earlier that lets you define what the tonal range is. I will leave that closed for now and save that for a later chapter. And then once you pick the Tonal Range, you could say, do you want to work only on the highlights that you define or only in the midtones or only in the shadows. Again, we'll save that for later. I've already adjusted the Gamma, Pedestal, Gain and you've seen these guys in the tonal correction movies.

Let's go down to RGB. In RGB you've got a Red Gamma, Red Pedestal, Red Gain, same thing for green, same thing for blue. This is where you adjust the individual channels, and you typically want to look at the RGB Parade as you adjust these channels and then also tangentially look at the Vectorscope to see what the general, the colorcast is. Right now it's kind of leaning toward blue down there. So as you make your fixes you can watch them over here, and pretty much you can see that right now, boy, I've got way too much blue here and not enough red.

So typically your workflow would be I'll take my Blue Pedestal, I'll bring the blue down a bit, so that the Shadows are a little bit farther down the line, and you can see that's showing up here in the RGB Parade. And I also bring down my Blue Gain, which is the top part, the Highlights part. It actually brings down everything, but it brings down the highlights as well. Then I probably want to bring up my red, the Red Pedestal is fine. Right now, it's really touching the bottom so it should be okay, but I need to bring up the red highlights, so I'll bring up the Red Gain. Eventually that will get up to the point where it might begin to start balancing this clip.

It kind of jumps around, as you can see, one of the issues about dealing with these guys, but there you go. We pretty much get that settled down. That's the basic way that you would work with the RGB Color Corrector. Now there are some other ways to work with it. You might want to work with the Crop tool and just work on a specific area and try to make that become gray, which we have done a pretty job. But these three things should line up here if it's gray, and they are pretty close to lining up. You can see we need to raise the red a little bit, drop the blue a bit, but we are approaching that and that is something you would try to do with the RGB Color Corrector or RGB Curves.

I explained this in more detail on that movie I mentioned before, "Fixing color cast, skin tone, and other color issues." Let's move on to the RGB Curves, turn off the Crop, and RGB Curves, And again, I have done the tonality work here already. You've seen this before in RGB Curve. You have seen and it's got the Master control, which is luma control, and you've got individual channels red, green, and blue. Let's take a look up in the top first though. Here is that dropdown menu again, and here is that Split view again, except the dropdown is a little different this time. It has only three things: Composite, Luma, and Mask. It doesn't have a Tonal Range Definition option.

Unlike the RGB Color Corrector, this is like one thing less than RGB Color Corrector. Just keep that in mind when you do the secondary color correction work. The mask is the same as the other one as well. That allows you to define an area that you can work in. So we'll stick with Composite. We won't worry about the Split view. It's the same concept. We'll go down here to these three curve controls, red, green and blue, and it's very much like working in the RGB Color Corrector, except here you're working with these curves. I want to bring the blue down, so I'll bring the Pedestal down first. In this particular case it's not called Pedestal.

It's called the shadows or the blacks. So bring them down, and it goes side ways to the right here. That brings them down. I want to bring down the highlights as well. I'll bring them down this way. Just like tonality, if you have the option of going left or down--left would be then up from the opposite of down-- if you have the option of going up or right then right is down. So I could bring these guys a bit. I'm bringing down the blue, and the thing about working with curves is that there is no numerical readout. You can type in a number or something like that. It's all just basically dragging until you think it's lining up okay, but you can't let's say, keyframe a number and maybe try a different number later.

It's all this kind of dragging process, which sometimes it could be a little bit of problem, because it's hard to really nail it perfectly. Let's go over to the red. Now I need to lift the highlights, so this would be down, so left must be up, so I'll go this way, and lift the highlights on the red. I'll try to compensate for the fact that they were not high enough before, and lo and behold, we're beginning to get this guy kind of settled in. Again, that's the process. You watch the RGB Parade, and as you're working with it, you can sort of see the effect that you've done. I also notice that the green is probably a little bit high, so I'll bring the green down just a touch.

That's basic approach to using this tool. If you look in the bottom, there is only one more disclosure triangular for the secondary color correction, so that is all you have to work with inside the RGB Curves. So these effects work on a color- channel-by-channel basis, and you work with them one color channel at a time to try to fix any color problems in your clips.