Get to Grips with Resolve’s Most Important Nodes: Serial, Parallel, and Outside
Have you ever looked at a DaVinci Resolve project and been completely overwhelmed by its apparent complexity? If so, it’s almost certainly the Node Graph that gave you this impression. But nodes are the building block of everything we do when grading in Resolve, so we have to cut through that complexity and reach a simple understanding of how nodes work.
So let’s take a look at how I use nodes in my professional color grading practice.
What is a node?
We start, of course, with the Node Graph, which you’ll see in the upper right-hand corner of the Color page.
By default, there’s just one single Serial node in the graph, and it’s an empty node. The Serial node is the default type of node when grading in Resolve. It’s called a Serial node because it happens in series, one after another. We’ll look at this in more detail in a moment. But before we do, we need to answer an even more fundamental question, “what exactly is a node?”
I’m going to give you my definition: a node is a visual idea of something we want to do to our image. Here’s what I mean by that.
Labeling your nodes
Before we start to make any adjustments, click on the empty Serial node and select Node Label to give it a name based on the idea that we intend to express. And the idea for node number one is exposure. We’ll be adjusting our exposure in the “Exposure” node. That’s all. When we have a new idea, we’ll create a new node for it.
So here in node number one, our Exposure node, we can adjust the Offset wheel in the Color Wheels tab based on where we think exposure should sit. Now we’re ready to move on to a new idea, like adjusting the contrast ratio of our image.
Working with Serial nodes
This is a new idea, so it belongs in a new Serial node, so we’ll create a new Serial node by navigating to Color->Nodes->Add Serial Node, or hitting Opt/Alt+S.
This creates a new node downstream from our Exposure node, and we’ll label this node “Contrast” because this is where we’ll be manipulating the contrast of our image.
What’s important to understand is that the starting point for a Serial node is whatever adjustment(s) happened in the nodes that came before it. In this case, that’s just one node, our Exposure node. So node number two is receiving whatever we did in node number one as its starting point.
Audition your adjustments with nodes
One of the benefits of containing your ideas within individual nodes is the ability to audition the adjustments within that node. You can toggle a node off and then on again to get a contextual view of what’s been affected in the image by selecting Color->Node->Enable/Disable Selected Nodes—or simply hitting Cmd/Ctrl+D.
So for example, by toggling just your Contrast node, you can easily see how well you’ve expressed your idea about the contrast in the image.
My go-to serial nodes
I always work with nodes in the same way when starting a grade. I start with exposure, move on to contrast, and then add a third serial node for balance. In our balance node, we can work on the simple idea of manipulating the relationship between red, green, and blue in this image.
So once again, hit Opt/Alt+S to create a new Serial node, right-click the node to select Node Label, and this time we’ll name it “Balance.”
Now you can make a simple adjustment by grabbing the middle point of the Offset color wheel in the Primaries tab and dragging it in whatever direction you want to take the image. Once you feel good about the result, you can toggle this node on and off (Cmd/Ctrl+D) to see how your adjustments are netting out on the image until you’re happy with the result.
So those are the three Serial nodes I always use in my workflow for any grade: exposure, contrast, and balance.
Enter the parallel node
As mentioned earlier, serial nodes are the default node, and you should use these unless there’s a reason to use another type. So let’s take a look at another type of node that I often use—the Parallel node
To create a Parallel node, go to your menu bar and select Color->Nodes->Add Parallel Node or press Opt/Alt+P.
You’ve now created a vertical stack in your node graph, adding a new node below and a Parallel Mixer node after our selected Serial node. What’s happening here is two nodes are being fed into this Parallel Mixer node in equal measure. Since they’re equal, it doesn’t matter which node is on top or bottom.
So why might you use Parallel nodes in your workflow? Right now, the Contrast node is the starting point for both our Balance node and our new node, indicated by the connection lines to the green inputs on both nodes.
But we’re going to disconnect the input into our lower node, node 04, and instead hook it up to the leftmost goalpost at the beginning of the node graph. Now, node 04 is receiving the initial state of the image, as opposed to whatever adjustments were made on the earlier Serial nodes.
Why are we doing this? What’s this all for? The benefit here is that we now have a separate branch in our node graph where we can make our secondaries adjustments.
In the top branch, everything so far has been primaries adjustments; changes that affect the entire image. Secondaries adjustments are adjustments that only affect a particular portion of the image. An example of a secondary is a hue versus hue curve, like making the yellows in our image just a bit more orange, around four degrees. It’s subtle, but that’s a great example of an adjustment that we might want to make in the course of a color grade.
A second branch for secondary adjustments
Now the reason why we’re making a secondary adjustment in a separate branch is that this adjustment depends on what’s fed into it, and responds accordingly. So let’s say we make all of these adjustments, and then the client says, “I think you went a little bit heavy on the contrast. We need to back off the contrast a little bit.”
If we’d just used another Serial node, it would be dependent on those earlier adjustments and subject to any changes that happen later on. That’s not what we want. We want any secondary adjustments that we make in our lower branch to happen independently of what happens up in the primaries branch. We want them to remain consistent even if we have to go back in and refine adjustments in the top primaries branch of our node graph.
So that’s how I use Parallel nodes in almost every grade that I tackle. It’s to have a separate branch for your secondaries, which isn’t dependent on what you’re doing in your primaries. It also means nothing will break as a result of changes to the image that feed into that secondary adjustment.
Pasting node graph templates
So far, we’ve built out a very useful two-branched structure in our node graph, and I’d like to use this as a starting point on a new clip. To start, we’ll select a clip that has yet to be graded—you’ll notice that the node graph has defaulted back to a single empty node. Next, right-click on the thumbnail for the previous clip, the one that contains the node graph, and select “Apply Grade.”
Effectively, this pastes a template with labels and a structure that works for me, and all I have to do is change the actual adjustments to reflect what I think this new shot needs.
Linking selections with the outside node
Now let’s take a look at a different type of secondary adjustment node. The Outside node.
Let’s say that our idea for this node is to ever so slightly soften the subject’s skin. We’ll create a new Serial node by hitting Opt/Alt+S, and then go to the power window palette and create a circular power window. Our goal here is to align this power window with the contours of the subject’s face so any adjustments are limited to the subject’s skin.
There are a number of ways that we could soften her skin, but for this example, we’ll use Mid-tone Detail and just pull it back slightly to soften things out. This is a great example of the type of subtle adjustment that we can make with our secondaries in this lower branch of our node tree.
Let’s now say we want to guide the viewer’s eye by taking down the exposure around the subject’s face. We could simply create a new Serial node, draw a new power window, realign it with our subject, invert that power window, and then lower the exposure outside our subject’s face. But there’s actually a better way to do this, using an Outside node.
An Outside node is simply a node that inverts the alpha transparency of the node that precedes it. Therefore, adjustments in an Outside node affect the opposite area of the previous node. Let’s look at what that means.
First, make sure the node with the existing power window is selected, then navigate to Color->Nodes->Add Outside Node, or hit Opt/Alt+O. Notice the Outside node has a new dotted line connecting its alpha channel to the previous node.
Let’s make this more clear. In the viewer, press Shift+H to enable Highlight mode to visually display what part of the image is selected.
Where before, we were affecting everything inside of the gray region, we’re now affecting everything outside of the gray region. The beauty here is if we decide to go back to our Serial node and reposition our power window, the new positioning will be updated in the Outside node.
Since the Outside node reflects the alpha channel of the earlier Serial node, it’s really the same mask married together. So we can now lower the exposure around our subject without having to create a new power window, which can obviously be very helpful. We can also drag to select nodes four and six and hit Cmd/Ctrl+D to audition the net result of both softening the subject’s skin and knocking down exposure around the subject.
The ultimate question: How many nodes?
The last thing I want to emphasize before we wrap up is a question that always comes up about node graphs: How many nodes should we have? How many nodes are too many? How many nodes are too few?
Well, we started to answer that question by simply defining what a node is or what a node should be. I gave you my definition that a node is an idea. So this gives us a simple formula: new idea = new node. That means we should have at least as many nodes as we have ideas.
“There are probably a lot of ideas in play. This is not always a great thing.”
That also means that when you see a complex node graph for a grade, there are probably a lot of ideas in play. This is not always a great thing. Usually, the more nodes that you see crowding a node graph, the higher the likelihood that the ideas have yet to be distilled down into their simplest and most essential form.
So, how many nodes should we have? How big should your node graph be? Well, it depends on what you’re doing, but it should be as small as it can be while allowing you to accomplish your creative goals and those of your clients.
While we didn’t cover all the node types in Resolve, hopefully you now have a fundamental understanding of the Serial node, the Parallel node, and the Outside node, and how to use them to craft great-looking images.