When it comes to deciding upon a professional reference display to add to your DaVinci Resolve Hardware setup, what are the things you need to look out for? Authors Robbie Carman and Patrick Inhofer discuss the importance of looking at what color spaces and gamma are supported by a reference display and how that can impact your workflow.
- One of the things we want to talk about when we talk about our reference displays are color spaces and gamma, and I've got Robbie here-- - What? - On the Google machine, and you're asking Google what's a color space. So, Robbie, what's Google telling you? - That everybody uses anything having to do with color science, terms like color space, gamma, etc., for the most part, incorrectly, is what it's telling me. - We all use the terms wrong. - Yeah, so the thing about this is that when it comes to common, what we refer to as color spaces, some people call it gamut, you're going to find color scientists out there, Pat and I, neither of us are color scientists, taking issue with the term, whether you're using it correctly or incorrectly.
That's not really the overall point of this movie. It's more to explain, hey, what you're going to find on your reference monitor. But just real quick, when it comes to the idea of color space, color models, and coding formats, it's really easy to think about a top down approach. You kind of have an abstract sort of thinking about what color is and how it works in the real world. Color scientists then take that and they put it into a smaller container, like an encoding format, like RGB or HSL or CMYK. - What they're doing is trying to find points that we can actually map to, targets that we can hit, and then, for us, manipulate.
- Right, and then in those encoding formats, we're going to have defined areas of volume that we can use for different purposes. That's that defined area that most people, when they say, "Hey, what color space does this do?" That's what they're thinking, things like Rec. 709, DCI-P3, Rec. 2020. When it comes to our displays, those are the three biggies, Rec. 709, P3, and the emerging one of Rec. 2020. - Those can be accurately described, I think, as color gamuts, because they define what are the colors living within here, and if your display says it can do 100% of Rec. 709, it means it can hit every single pixel of color within that color gamut.
- Correct, so if you are working with HD video, you want to make sure you have a display that can do 100% of Rec. 709, otherwise, you're going to have images that are clipping, that are not showing you the full amount of color that is possible within that cutout of Rec. 709. Same thing with DCI-P3. A lot of displays claim they can do P3, but they might not do 100% of it. If most of your work is for cinema, and you're working in P3, well, you need a display that can actually do 100% of P3, not just 90% of it.
Now, the outlier is Rec. 2020. - [Pat] Rec. 2020, yeah. - [Robbie] There's no display that currently does 100% of Rec. 2020. - [Pat] In fact, we can't even really get close. I mean, we're at, what, 80%? - [Robbie] Yeah, laser projectors can do a lot more than traditional direct view sets, but it's something that's emerging. Eventually, display technology will improve enough that we'll probably be able to do that. But the thing about these larger spaces is that we have more volume available to us. Think about it as having the ability to make something really true red, in, say, Rec. 2020, where it might appear to be kind of orangey red in Rec. 709.
Just more color volume to work with. Now, as a general rule of thumb, when it comes to hardware, your reference monitor, DaVinci Resolve, we just want to make sure that all the pieces are playing-- - That everything matches up, right? - Right. If I'm working Rec. 709 in DaVinci Resolve, I want to make sure that I'm monitoring Rec. 709. Most modern reference monitors are going to have selectable color spaces, are going to allow you to switch between these common ones like Rec. 709, P3, and 2020. Now, Pat, there's another term that I think confuses a lot of people, and that's gamma.
You might also hear of gamma described as the EOTF, if you want to win Jeopardy, that stands for the electro-optical transfer function. But basically, gamma or EOTF kind of refers to the non-linear display of brightness on an actual monitor to better mimic how we see the real world. - [Pat] Yeah, and basically what it does, instead of going from zero black to 100 in a straight line, you're going from black to white kind of in a weird kind of slow-- - [Robbie] A weighted curve. - A weighted curve, and when we select different gammas, we change the shape of that curve.
The end result is, some gammas look a little more poppy, a little more contrasty than other gammas, and the important thing to realize is, you're going to select a gamma that kind of is used often, but not always defined by the gamut that we're trying to hit, like DCI-P3. - Right, so, for example, if you're doing DCI-P3, that has a gamma of 2.6 for digital cinema. If you're doing HD video-- - It gets a little more wonky. - It's a little wonky. A lot of people will claim that 2.2 gamma is the correct one to choose.
That's kind of how it used to be for broadcast and a lot of HD video work, definitely the way it has been for the longest time for computer displays. There's been debate, lots of studies, maybe, hey, maybe it's 2.35, which the BBC was advocating for a long time. Cutting through all of that, these days, most professionals will agree and the standards bodies also recommend that a gamma of 2.4 for HD video is good for a true reference environment. - [Pat] Yeah, and so if you're going to be selling yourself as a professional colorist, you're delivering, say, for broadcast at Rec. 709, generally, you're going to be very safe if you select 2.4, because the important thing to remember is, Rec. 709, that specification doesn't define a gamma, and that's where a lot of this confusion comes into play.
- Right or has in the past. The standards bodies have gotten on top of a little bit of that. - Yeah, they've started defining it now. - But it still confuses a little bit. - But the industry has pretty much said, you know what, 2.4, let's all kind of agree to agree. - Now, there's a couple other related terms, that as you're looking at hardware and monitors that might kind of bring up some more confusion, a related EOTF that's new on the scene that's called BT.1886, I won't bore you with the math, but basically traditional gamma power functions, like 2.4 and 2.6, were kind of assuming that you had a display that could do perfect black. Most displays, outside of OLED, can't do that, so these guys got together and said, "Hey, let's make a better curve that better reflects "the actual black level performance "of most LCD/LED type displays." You often see BT.1886, that's fine to use for a lot of displays, again, the math is a little different than a power function.
Then you might also see something described as a straight up EOTF, like for example, Dolby with HDR work, now describes things like ST-2084 as the Dolby PQ EOTF. Again, a little beyond the scope of this title, but when it comes down to it, the main takeaways here are making sure that your color space workflow from what you're doing in Resolve matches what your monitor is, both for your gamut as well as your EOTF. - Exactly, and BT.1886, just to circle back for a moment, if you're on an OLED, it's a 2.4 gamma function.
- It's a power function, yeah. - That's exactly what it is. It's only when your black levels start rising on an LCD that it deforms a little bit away from that. But otherwise, it really is a 2.4 if you've got something like an OLED. - It just tracks a little bit better in the shadows, for sure. - Exactly. To wrap this up, we're going to talk next about working with UHD and HDR reference monitors.
- Understanding Linux, Mac, and Windows Resolve systems
- Key hardware components: CPU, RAM, and GPU
- Video reference monitors
- Control surfaces
- Hardware accessories for color correction