What is the real difference between ACES and Resolve color management? Even if we understand these tools individually, most of us lack a clear and simple understanding of how they relate to each other. As a result, we don’t know how to evaluate or choose between them.
In this article, I’m going to show you how each system works inside DaVinci Resolve and how you can meaningfully evaluate each one so you can choose the best solution for your color grades.
Color managing with ACES
It’s time to get clear on what ACES is, what Resolve color management is, and how they relate to each other. Let’s start by talking about ACES. If you want to go more in-depth on ACES, I recommend checking out my ACES Explained series. But for today, let’s summarize ACES by saying that it is a color management framework.
What is a color management framework? A color management framework is simply a system that allows us to automatically transform what the camera sees into what our display can reproduce on an automatic basis.
What does that look like? What does that mean? Let’s take this image as an example. It is a Log image right now, meaning that it is in the original color space of the ARRI Alexa camera it was shot on.
To begin grading this, we need to introduce quite a bit of contrast and saturation. We could go down to the Primaries and start spinning wheels until we begin to get an acceptable result. But that might not be the best workflow. Instead, we’re going to take a color management approach to solve this problem.
To do this, we’re going to use ACES. First, go to the file menu and choose Project Settings. Then, under Color Management, go to the Color Science dropdown menu. Instead of DaVinci YRGB, select ACEScct.
ACEScct exposes a couple of additional options below that dropdown menu. ACES Input Transform is simply asking for the state of the image when it was initially dropped into this timeline. In our case, all of the images came from an ARRI camera, so that’s the input transform we’re going to select.
Next, we have the ACES Output Transform. This is asking what display we are outputting to. In my case, I am outputting to a Rec.709 mastering monitor. So, that’s the option we’re going to select from this dropdown menu.
Pay attention to what happens to the image when we hit Save.
All of a sudden, the image has a healthy level of contrast and saturation, right? And that’s not all. Now, it’s the case for every image in oue timeline. All of the Log images have been normalized. In other words, we have transformed what the camera captured into what our displays can reproduce. That is color management in a nutshell.
Color managing with Resolve color management
Now that we’ve seen the ACES color management framework, let’s talk about Resolve. Resolve color management is simply another color management framework, just like ACES. But why do we even have this choice? Why do we need two systems?
ACES and Resolve color management simply represent two solutions to the same fundamental problem. Let’s say that, instead of color managing with ACES, we want to color manage with Resolve color management. Let’s take a look at how that works.
First, go to the file menu and choose Project Settings. Once again, select Color Management. But for Color Science, instead of choosing ACEScct, click on DaVinci YRGB Color Managed. This is how to select Resolve color management.
We need to navigate these options in a very specific way. If you are new to Resolve color management, the first thing to do might seem a bit counterintuitive. We’re going to turn off Automatic color management. We’re doing this because the Automatic color management system actually hides the very thing that we need to understand. So, let’s uncheck that box.
When the Automatic color management box is unchecked, the Color processing mode is revealed. Because I want you to get an explicit look under the hood, scroll down to the bottom of the dropdown menu and choose Custom.
By unchecking Automatic color management and selecting Custom, I have given us access to the full range of options available in Resolve. As you get more familiar with Resolve color management, you’ll be able to utilize all the presets in this menu. We will use them when we enable Automatic color management. These presets are there for you to use and you should not be afraid of them.
Differences between ACES and Resolve color management
For now, we just want to familiarize ourselves with Resolve color management and how it it differs from ACES. Let’s explore these new options and how they align with ACES.
First, look at Input color space. This is simply a different term for what ACES calls the ACES Input Transform. This is where we tell the color management framework what the color space of our source is. In this case, scroll down and select ARRI Log C because that is the color space of our images.
Next, we have our Output color space. ACES calls this the ACES Output Transform. Similarly, Rec.709 Gamma 2.4 is the same thing as what ACES calls Rec.709. These two options are the same as the ones we have when we are setting up an ACES color management workflow.
Everything else that you see here is unique to Resolve color management. These are options that you can’t control when using ACES. The terminology, user interface, and number of accessible parameters are different between ACES and Resolve color management.
Neither one of these is necessarily better than the other. It depends on how you are working. If you want to get a solid color management framework quickly and don’t know how to use all of these settings here, ACES might be a good place to start. Or you might choose to go to one of the preset modes that we skipped over in Resolve color management. But there are additional options that you can control in Resolve if you want to.
Let’s look at the next key difference between Resolve color management and ACES. Right now, all I’ve done is change from ACES in my Project Settings to Resolve color management. We still have ARRI Alexa as our Input and we still have an Output of Rec.709. Our settings are essentially exactly the same. So, what happens when we hit Save?
The image changes a bit, doesn’t it? Even though our color management frameworks are set up identically, we are getting two different visual reproductions of the image. This is something you should consider when you are deciding between ACES or Resolve color management.
If Resolve color management looks significantly better than ACES, that would be a completely valid reason to select Resolve. The reverse is also true. If you like how ACES looks, that is a completely valid reason for using ACES on your project.
Exploring Resolve’s color management presets
Now that we’ve seen where ACES and Resolve align and how they differ, let’s go back to Project Settings and explore some of the presets in Resolve color management.
Here’s something I would encourage you to do if you are using Resolve color management for the first time. Leave the Automatic color management off and select HDR DaVinci Wide Gamut Intermediate as your Color processing mode. This is a great preset to select unless you have an explicit reason to choose something else.
Once you select HDR DaVinci Wide Gamut Intermediate, you’ll see that your big long list of options largely goes away. All that is left is the Output color space, which will usually be Rec709 Gamma2.4. That’s all you need to set up in this menu. Remember to hit Save.
There’s one other parameter that we still need to make sure is properly set up if we want to get sound color management. That is our Input color space.
When you are using the preset HDR DaVinci Wide Gamut Intermediate, you won’t see your Input color space in Project Settings. You’ll have to find it another way. To do this, right-click on your individual clip to bring up the menu. There, you’ll find Input color space.
We need to make sure that that input color space matches our camera. In this case, it’s already correct. This clip is already in ARRI Log C3. But we need to make sure this is the case for every clip in my timeline. We could go through each clip one-by-one, but if all of the shots in the timeline are in one color space, it’s better to hit Command-A to select all of the clips. Then, right-click and set every Input color space to ARRI Log C3 in one stroke.
Now, we have completed our Resolve color management setup. This is how I would recommend getting into Resolve color management if you’re brand new to it.
One final difference between ACES and Resolve
The last thing I’ll point out is that the Input color spaces available in ACES are not identical to the ones in Resolve color management. In some cases, you are going to find a preset for a particular camera in Resolve color management that is not available in an ACES pipeline.
This could be another completely valid reason to use Resolve color management over ACES. If your camera is not listed in the available Input color spaces inside of ACES, you might want to go with Resolve color management to ensure that you are properly inputing your material.
Color management can be a daunting subject at first. Ultimately, you need to understand what ACES is, what Resolve color management is, and what the differences are between them.
However, it is just as important to commit to whatever color management framework you choose. You can get great results out of both ACES and Resolve color management. But once you’ve selected one, you must commit to it. The worst thing that you can do is second guess your color grade midway through your process. Once you have made a choice, stick with it.
At the end of the day, the choice between ACES and Resolve color management is a bit like choosing between two high-end cinema cameras. Both can give you great results and both merit exploration and testing rather than assumptions based on someone else’s workflow.
If you’re new to color management or you’re under a tight deadline, there’s nothing wrong with sticking to what you know. Just remember that in the long run, learning is your most important task as a colorist.