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SDR color volume is a representation of a TV's color performance when displaying SDR content. Ideally, you want a TV with large coverage of the DCI-P3 and BT.2020 color spaces so your SDR content is as colorful and accurate as possible. Instead of showing a TV's color volume performance with a 3D graphic as we do with our HDR Color Volume test, our SDR color volume test shows us a display's capabilities with an easier-to-understand 2D image, which is broken down into slices called gamut rings.
Test results
Test Methodology Coverage
We added this test as part of our 2.0 test bench update. Before that, we had no equivalent test, so TVs that haven't been tested on 2.0 or later don't have these results. Learn how our test benches and scoring system work.
| 1.11 | 2.0 | |
|---|---|---|
| SDR Color Volume | CIELAB DCI-P3 Coverage | ❌ | ✅ |
| SDR Color Volume | CIELAB BT.2020 Coverage | ❌ | ✅ |
When It Matters
Although the vast majority of SDR movies and shows utilize the smaller Rec.709 color space, there are some that take advantage of the wider DCI-P3 and BT.2020 color spaces. There are also a lot of SDR video games that take advantage of these wider color spaces, so SDR color volume is important if you want varied, vibrant, and accurate colors.
Our Tests
We start off by calibrating the TV and setting diffuse white to 100 cd/m², as that's the consensus value for SDR content. We then make sure that the TV is fully warmed up. After that, we calibrate our Colorimetry Research CR-100 colorimeter to the TV using a Colorimetry Research CR-250 spectroradiometer. For this test, we set the TV to its largest color space, which is typically the Native setting.
With our CR-100, we take 602 individual measurements in a dark room through our Calman software workflow. Once these measurements are complete, we're left with Cube Data as well as Target & Intersect Data for the DCI-P3 and BT.2020 color spaces, giving us objective measurements of the TV's SDR color volume performance.
CIELAB DCI-P3 Coverage
Once we have the data for the DCI-P3 color space, Calman generates the 2D gamut rings diagram, which shows how much of the color space can be shown by the TV. The gray areas around the edges of each individual ring show the space that a TV can't fill. Using the Panasonic Z85A as an example, we can see that the data shows the TV covers 92.46% of DCI-P3, and by looking at the graph, we can easily see that it can't display very light colors.
| Data | Final Results Visualized |
 |  |
CIELAB BT.2020 Coverage
Since the data for both color spaces is generated when the initial measurements are taken, there are no additional steps for the BT.2020 color space. By looking at the data, we can see that the Panasonic Z85A covers 62.67% of the BT.2020 color space. The 2D diagram shows that even with darker colors, the TV struggles a bit. However, we can plainly see that as colors become lighter, the TV's coverage of each individual ring decreases drastically.
| Data | Final Results Visualized |
 |  |
Additional Information
The SDR Color Volume test uses the CIELAB color space, which differs from the ITP color space we use for the HDR Color Volume test. As of the time of this article's publication, the general consensus is that ITP should be used to analyze the color performance of displays in HDR using the PQ EOTF. On the other hand, the general consensus is that CIELAB is appropriate for characterizing the color performance of displays in SDR. The primary reason is that CIELAB doesn't use brightness, but rather Lightness (L*).
At its maximum value, L*=100 should be equal to diffuse white, meaning the white level to which the observer is adapted when watching content. In SDR, the consensus value for this is 100 cd/m². CIELAB doesn't have a defined value above L*=100, and there is no consensus on the luminance level of diffuse white in HDR, so CIELAB is best suited for SDR.
It's important to note that the industry is constantly evolving, and there are regularly new developments in evaluating a TV's color performance. We want our tests to be as useful and up-to-date as possible, so we keep a close eye on breakthroughs in the academic field. For example, there's currently uncertainty in the industry about whether gamut rings are appropriate for HDR color performance. If the general consensus shifts, we would be completely open to exploring HDR gamut rings.
Conclusion
Our SDR color volume test shows how well a TV can display the range of colors in the DCI-P3 and BT.2020 color spaces. With whites calibrated to 100 cd/m², you can see the exact percentage of colors a TV can show in each of these wide color spaces. Instead of looking at a complicated 3D graphic, gamut rings allow you to see the range of colors a TV covers in SDR with a simple 2D diagram.
Acknowledgments
We'd like to acknowledge Dr. Kenichiro Masaoka of the NHK for his pioneering work in developing gamut rings. His contributions have significantly advanced our understanding of color gamut visualization, helping researchers and industry professionals analyze and compare color reproduction more effectively. We would also like to acknowledge Dr. Euan Smith for the development of the gamut rings intersection diagram we use in this test.
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