Join Robbie Carman for an in-depth discussion in this video Using curves, part of Premiere Pro Guru: Lumetri Workflows using SpeedGrade and Direct Link.
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Now I get it. For some people, the color balance controls, meaning the color wheels and the contrast sliders inside of SpeedGrade, especially because there are twelve of them for different parts of the tonal range, can seem a little confusing and a little intimidating. Furthermore, there are a lot of people that know how to color correct and grade, they've just never done it with color wheels that are common on video color correction tools. Instead, a lot of people are used to using curves.
If you have a photo background or if you've used Photoshop a lot, no doubt you have used curves. And in this movie, I want to show you the curves inside of SpeedGrade. So I've gone ahead and opened up this timeline, O3O5, using curves, and I do just have to point out that curves are something that are relatively new to SpeedGrade. In previous versions of SpeedGrade, we never had curves. And myself and others always explained away the lack of curves because we had, you know what, twelve way color corrector.
A twelve way color corrector, if you use it like a twelve way color corrector, can mimic curves. But for a lot of people, that still wasn't good enough, and they were much more comfortable with the curve interface of the traditional set of curves. So on this shot, I have a grade that I've already applied, and you know, as I play the shot, it looks pretty good. But what I want to go ahead and do is turn off this grade. I'll do that by pressing the little eyeball icon next to that primary layer. And the way I find curves is not all that intuitive.
There's not a layer type labeled "Plus C", C for curves. Instead, what I need to do is click on this plus button right here to get a custom look layer and you'll notice that there's a category right here for curves. Now I have two types of curves. Let's first visit RGB curves. So we'll go ahead and add RGB curves by selecting them, and right here, I now have my curves. Now I have four curves inside of the curves interface. I have a Luma only curve and then I have a red, green, and blue curve right here.
And next to each curve, I have a little reset icon. So if I screw something up, I can press the reset icon to reset that curve. As you hover over the curve, you'll notice that you get a little dot or a control point at that point of the tonal range. Now the way curves work of course is that the tonal range, from black, down here in the left hand corner, is mapped all the way through, from gray here in the middle, up to white. And when you add a control point, you can essentially remap the image at that portion of the tonal range.
So for example, if I want to add a control point down here, I can do that simply by clicking. And then if I hover over it, you'll notice that it becomes blue and I can click and drag and change my contrast at that portion of the tonal range. In this case, if I drag down, I'm making things darker, or drag up, and I'm making things brighter. So I'll go ahead and just add a little bit more contrast there and let's come up to the top part of the tonal range and I'll add another curve control point right there. And maybe I went a little too heavy handed on the shadows. And then I'll come into my mid-tones and I'm kind of creating a very, contrasty, kind of filmic, little s-curve there.
Not for everybody, but I'm kind of liking it right now. And of course, if I want to adjust this, I can click on any control point, and then simply just reposition where I have that curve just like that. If I want to reset that, I'll simply press the reset button. Okay, the color curves work in a very similar fashion. The tonal range is mapped from shadows down here, up to whites over here. Now, for example, if I click on the red curve, right here in the mid-tones, if I drag up, I'm going to be adding red in at that portion of the tonal range.
If I click and drag down, I am subtracting red. Well, what does "subtracting red" mean? A lot of people kind of find this concept a little counterintuitive. The best way for me to figure this out and how I learned to realize what subtracting red meant, was by pressing A on my keyboard to bring up my analysis tools and if I go ahead and change this to a one scope layout, so we have a big scope, and look at the vectorscope, you can see the red target right here. What's opposite red on the scope, well that's cyan.
So as I drag down on the red curve, I'm actually adding more cyan into the image. If I added green and then subtracted green, you guessed it, I'd be adding magenta. And blue, opposite of blue, on the color wheel, would be yellow. So the color curves are pretty intuitive, just like the Luma curve, if you add a control point and drag up you're adding that color, down, you're subtracting that color at that portion of the tonal range. Personally, I find curves to be kind of a little bit of a time suck. If you have hundreds or thousands of shots to color grade, and you're grading them using the curves, the next thing you know, you've added dozens of control points along the tonal range and you've spent a lot of time just kind of tweaking the image.
What I often do with a new RGB curves, is I do a base grade with a primary layer in the twelve way color correction tools, and then if I need to, I'll come in with the RGB curves and just tweak a specific portion of the tonal range. Okay, there is another type of curves that we have here though. I'm going to go back and turn off my RGB curves. In fact, I'll click on the little trash can icon down here in the lower right hand corner to delete that layer and I'll turn my original grade back on. Now I like this original grade, but kind of distracting is this yellow here in the background.
So if I come back down and click on my plus button again, and then go back to curves, there's a different type of curves called Hue/Sat, and if I click on those, now what I see is the color spectrum mapped from red to red, going from left to right, and this curve will allow me to desaturate certain portions of the color spectrum. I can click on these preset buttons for red, yellow, green, and so on, or I can manually click and add a control point anywhere along the color spectrum. And the way that this works, let me go ahead and press yellow for example, is I press yellow and it adds a control point and then two other control points on either side.
They kind of limit that correction. By the way, you can do the exact same thing on the Luma red, green, and blue curves that I showed you a moment ago. So now that I have yellow selected, I'll come down here and drag this middle point and kind of just desaturate yellow just a little bit, and I might need to widen that out just a touch. Let's go ahead and do that, there we go. And I'll drag down even further. And if I toggle that on and off, yeah, you can see that it really sort of desaturated that yellow back there on that sign.
And this curve is great for doing things like adjusting the intensity of grass, or a sign, or somebody may be wearing a bright red sweatshirt that's a little too intense. This curve is also really good for doing leave color behind type looks. Let me go ahead and reset this curve. I first need to turn it on. Then I'll come over and reset it. And for example, maybe I really like that yellow, so I'll identify yellow right there, I'll take this curve and drag this control point down, and then we'll add a new control point right here, and so yeah, now what we're doing is really just leaving yellow in that image and desaturating everything else.
So I think you can see that the curves are a welcome addition to SpeedGrade. And if you've used curves before, especially the Luma, red, green, and blue curves, those should be really familiar to you. If you haven't ever used a hue saturation curve before, take some time to play with it. It's an immensely powerful tool for tweaking saturation at various parts of the color spectrum.
- Applying Lumetri look presets to clips and adjustment layers
- Combining presets with other color corrections
- Sending a project from Premiere Pro to SpeedGrade and back again
- Merging clips in the Timeline
- Matching clips
- Using Lumetri looks in Photoshop and After Effects