Achieving a “Look” with the ColorCorrect Node
Giving an image a “look” is a very different practice than matching color. While matching color has a very specific purpose and methodology, giving an image a look refers to an artistic practice that gives an image a different feel to how it was shot. For example, you might want it to look brighter, warmer, or colder, depending on the feeling you want to create.
Using the ColorCorrect node
The ColorCorrect node is a very good tool to use for this, as it has a lot of control over the different parts of the image—even more control than the Grade node. But as with everything else, it is still made out of the basic mathematical building blocks covered in the beginning of this chapter.
Let’s bring in an image and give it a look.
- Press Ctrl/Cmd-W to close the color matching script and start a new one.
- Press the R key and bring in, from the chapter04 folder, the car.png image again.
- While the newly imported Read1 node is selected, press the C key to create a ColorCorrect node. You can also find the ColorCorrect node in the Color toolbox.
View ColorCorrect1 in the Viewer (FIGURE 4.44).
FIGURE 4.44 The ColorCorrect node’s Properties panel
As you can see in ColorCorrect1’s Properties panel, the ColorCorrect node includes controls for Saturation, Contrast, Gamma, Gain (Multiply), and Offset (Add). These properties are available over either the whole dynamic range—called Master—or parts of the dynamic range called shadows, midtones, and highlights. Having individual control over the different areas of the dynamic range makes creating a look somewhat easier.
This idea of midtones, highlights, and shadows changes from image to image. An image of a dark room will have no whites, but in that darkness, you can still pick out the brighter areas that are the image’s highlights, the slightly lighter blacks that are the midtones, and the darkest colors that are the shadows. You can also define these in the ColorCorrect node’s Ranges tab.
Click the Ranges tab in ColorCorrect1’s Properties panel.
In this tab (it’s similar to ColorLookup, isn’t it?) you have three graphs, all selected. One represents the shadows, another the midtones, and a third the highlights (FIGURE 4.45).
FIGURE 4.45 ColorCorrect’s Ranges is a lookup curve that defines the brightness ranges.
Click the Test check box at the top of the graph (FIGURE 4.46).
FIGURE 4.46 The test shows the parts of the dynamic range in the Viewer.
This shows a representation in the Viewer of what parts of the image are shadow, midtone, and highlight. Highlights are represented by white, midtones as gray, and shadows as black. Green and magenta represent areas that are a mix of two ranges.
Click the Test button at the top of the graph again to turn it off.
The ranges are fine for this image, so we won’t change anything and will continue working.
Switch back to the ColorCorrect tab.
You will now give this image a dreamy, car commercial look—all soft pseudo blues and bright highlights. If you don’t define the look you are after in the beginning, you can lose yourself very quickly.
Before changing the color of this image, I’ll show you my preferred interface setup for color correcting.
In ColorCorrect1’s Property panel, click the Float Controls button. This will float the Properties panel instead of docking it in the Properties Bin (FIGURE 4.47).
FIGURE 4.47 Click the Float Controls button to float the Properties panel.
Hover your mouse pointer in the Viewer and press the spacebar to maximize the Viewer to the size of the whole interface (FIGURE 4.48).
FIGURE 4.48 This is a good way to set the interface for color correction.
Since the Properties panel is floating, it is still there. This way, you can look at the image at its maximum size without wasting space on things like the DAG, yet you are still able to manipulate the ColorCorrect node.
What I am aiming for is something like that in FIGURE 4.49. You can try to reach this look yourself, or you can follow my steps.
FIGURE 4.49 This is the image look I am referring to.
Let’s start by desaturating the whole image a little, so in the Master set of properties, set the Saturation property to 0.5.
Now for the shadows. I would like to color the shadows a little bluer than normal.
Remember, in addition to the In-panel Color Picker, you can also use the Floating Color Picker. To use this, Ctrl/Cmd-click the the Color Picker button. The benefit of using the Floating Color Picker is that all sliders also have Input fields, so you can type things up numerically.
Ctrl/Cmd-click the Color Picker button for shadows.gamma (FIGURE 4.50).
FIGURE 4.50 The Floating Color Picker
From the Hue slider, choose a blue hue. I selected 0.6. Now change the Saturation for the shadows.gamma color. I set it to 0.31. Finally, adjust the brightness, or Value slider in the Floating Color Picker. I have it at 1.22 (FIGURE 4.51).
FIGURE 4.51 Setting the shadow’s Gamma properties using the Floating Color Picker
This results in RGB values of 0.8418, 0.993, and 1.22, respectively. It gives the image a nice-looking blue shadow tint. Notice that there are actually no hue and saturation sliders in the real Properties. The hue and saturation sliders in the Floating Color Picker are there only so it will be easier to set the RGB sliders.
- Close this Floating Color Picker.
- You have a lot more work in the midtones. First, set the Saturation to 0 so that the midtones are tinted black and white.
- To create a flatter palette to work on, set the Contrast for midtones at 0.9.
- To darken the midtones, set the Gamma to 0.69.
- Use the Gain property to tint the midtones by Ctrl/Cmd-clicking the Color Picker button for Midtones/Gain.
In the Floating Color Picker that opens, click the TMI button at the top to enable the TMI sliders (FIGURE 4.52).
FIGURE 4.52 Turning on the TMI sliders
If you need to make the Floating Color Picker bigger, drag the bottom-right corner of the panel.
- Now, for a cooler looking shot, drag the T (temperature) slider up toward the blues. I stopped at 0.72.
- To correct the hue of the blue, use the M (magenta) slider to make this blue either have more magenta or more green. I went toward the green and left it at –0.11.
Close the Floating Color Picker (FIGURE 4.53).
FIGURE 4.53 The values are always in RGB.
As always, only the RGB values affect the image. You just used TMI sliders to set the RGB values in an easier way.
- You now increase the highlights a little, so let’s start by setting the Contrast to 1.5.
- To color correct the highlights, first click the 4 icon to enable the individual Gain input fields.
Click in the right side of Gain’s first input field (for the red channel) and use the up and down arrow keys on your keyboard to change the red value. I left it on 0.75 (FIGURE 4.54).
FIGURE 4.54 The arrow keys make it is easy to nudge values in input fields.
Leave the next field (green) where it is, but use the arrow keys in the blue field to increase blue. Because I want everything to be a little bluer, I left mine at 1.5.
The first stage of the color correction is finished. Let’s bring back the rest of the interface.
Close the ColorCorrect1 Property panel (FIGURE 4.55).
FIGURE 4.55 This is how to close a floating Properties panel.
- Press the spacebar to bring back all your panes.
Using the mask input to color correct a portion of the image
Let’s say that a commercial’s director asks for the wheels to pop out of the image and have high contrast. To do this secondary color correction, first you need to define an area to apply the color correction to, then you need to use another color node and use this area in its mask input.
You haven’t learned to create complex mattes yet, but in this case, you really need only two radial mattes. You can create those easily using the Radial node in the Draw toolbox.
First, to brighten up the wheels, use the Grade node.
Select ColorCorrect1 and insert a Grade node after it.
If you use the Grade node as it is, the whole image gets brighter. You’ll need to use Grade1’s mask input to define the area in which to work.
With nothing selected, create a Radial node from the Draw toolbox (FIGURE 4.56).
FIGURE 4.56 Creating an unattached Radial node
It creates a radial, see? I told you. By moving the edges of the radial box, you can change its shape and location.
- View Grade1.
Drag Radial1’s edges until it encompasses the back wheel (FIGURE 4.57).
FIGURE 4.57 Radial1 encompasses the back wheel.
You’ll need another Radial node to define the second wheel. (You can add as many Radial nodes as you need. Everything in Nuke is a node, remember?)
- With Radial1 selected, insert another Radial node after it.
Adjust Radial2 to engulf the front wheel (FIGURE 4.58).
FIGURE 4.58 Using Radial nodes to create masks for color correction
To make use of the radials, take the mask input for Grade1 and attach it to the output of Radial2, as in FIGURE 4.59.
FIGURE 4.59 Attaching the mask input to the mask image
This means whatever you now do in Grade1 affects only where the radial’s branch is white.
- Increase the whites by bringing the Whitepoint property for Grade1 down to around 0.51.
- Some of the deep blacks have become a little too gray, so decrease the Blackpoint property a bit. I left mine at 0.022.
At this point, the grading is finished. Mask inputs can be very important in color correction because a lot of times you want to color correct only an area of the image. But remember not to confuse mask inputs with mattes or alpha channels. The use of the mask input is solely to limit an effect—not to composite one image over another or to copy an alpha channel across.