As HDR video becomes increasingly mainstream, the push for wider color gamuts has led to debates over the practicality of using Rec.2020 as a mastering standard. Experts caution that Rec.2020’s wide color gamut is impractical for real-world use. From energy inefficiency and metameric failure to challenges in gamut mapping and a lack of compliant displays, the technical and creative hurdles of Rec.2020 are significant. This article compiles insights from industry professionals on why embracing Rec.2020 may do more harm than good.
“People’s relation to color films is precisely the same as it was in relation to the first Talkies. When sound was first introduced, people were so astonished that they wanted to hear moving pictures talk endlessly like actual people. The upshot of this was that initially there were lots of films filled with songs catering exclusively to this sense of wonderment. It was impossible to attend to aesthetics. When the novelty of talking pictures wore off, people started to understand that sound is not supposed to be deployed for its own sake but must have some aesthetic function… What will popular taste demand next? Those who watch films will expect to see the brightest of clothes, the reddest of cheeks, the most colorful flowers, and all manner of furniture in color films, and they will expect each of these to be the brightest and most garish colors; whether this strengthens the basic visual power of a film and its impact or ruins them will be irrelevant.”
– Muhammad Hasan Askari (1919 – 18 January 1978). Introduced, translated and annotated by Ali Nobil Ahmad)
Samsung Display: Rec.2020 Must Be The New Standard
At the 2023 OLED Korea Conference held in Incheon on April 13, Samsung Display’s Vice President of Strategic Marketing insisted that the display industry must switch from P3 To BT.2020, declaring,
“To implement optimal HDR for high-definition content, we need to set a new standard for color in the display industry.” Concerning which, he added that it’s vital to “switch the color gamut standard from the current DCI-P3 to ‘BT.2020 (UHD (4K) color specification established by the International Telecommunication Union (ITU))’, and consider the color volume that can represent the same color at any brightness.” “The color luminance of red (R) green (G) blue (B) three primary colors is a more important picture quality characteristic in consumer real-use environments than the luminance measured on the white screen,” he added.
“We don’t actually know what the ones and zeros that we’re putting on the drives are actually telling us”
Yet, commercialized reference grading monitors can’t attain Rec.2020; and consumer devices struggle to even cover industry-standard P3. Patrick Inhofer, CEO, Mixing Light, put the issue front and center,
“We’re in a situation now where the color volumes we’re working at, the nit ranges we’re working at, the brightness values we’re working at, exceed the ability of any modern display to reproduce. When HDR came out, the specifications were designed to exceed our ability to actually see it today, with the knowledge that eventually we will be able to have displays that can fully show us the full color volume at the full brightness range. So we’re working under specifications that exceed our deliverables. And in many cases, all of our work, technically, I think – probably all of the work we’re doing at any level – is somewhat compromised by that. We don’t actually know what the ones and zeros that we’re putting on the drives are actually telling us.”
Rec.2020 Never Intended As Native Device Primaries
Meanwhile, industry consultants are not all in agreement that it makes sense to master in Rec.2020.
“The BT.2020 developers appreciated that color processing would be necessary in all consumer devices; their goal was to standardize interchange or container primaries, not native device primaries. Nonetheless, some factions today assert that BT.2020 defines a colorspace suitable for program material—in other words, they argue that program material should be allowed to be mastered to the entire BT.2020 gamut. […] We believe that it is a mistake to create programming that addresses the entire gamut of BT.2020 colorspace. To do so risks compromising color image quality for a wide diversity of display devices, particularly in the cinema, where direct-view LED displays are emergent. We argue that BT.2020 colorspace should be considered an interchange or container space, as its developers intended. We believe that DCI P3 primaries are optimum for production and presentation of programming and for consumer imaging, and we believe that professional (BT.709/BT.1886) and consumer (sRGB) imagery will migrate to P3 primaries..” Charles Poynton, David LeHoty
“Rec.2020 is the ITU Recommendation for UHDTV. Included in the Recommendation is the UHDTV container color space, commonly known as “Rec. 2020,” designed to incorporate Pointers Gamut. However, emphasis must be placed on the word “container,” as practical displays cannot implement Rec.2020. Unlike digital cinema, the ITU does not define a minimum UHDTV display gamut to guide manufacturers and artists.” – Michael Karagosian
Edit 02.06.2025: It turns out that Dr. Kenichiro Masaoka actually did intend Rec.2020 as a mastering color space after all. We reached out to the ‘father’ of Rec.2020 to settle the controversy, writing:
“There appears to be some controversy whether Rec.2020 was developed as native device primaries that would be used to master program material or if it was conceived of primarily to standardize interchange or container primaries. Your input would be very welcome!”
Dr. Masaoka responded:
“The former is correct. I designed the chromaticity coordinates of the BT.2020 RGB primary set assuming the use of laser light sources (cf. IEEE paper attached), but also considered the possibility of achieving over 90% coverage using quantum dots (cf. Optics Express paper attached), which is now considered an appealing design goal in the market.”
Dr. Masaoka’s email corroborates the papers: Rec.2020 was engineered as a forward-looking mastering space, contingent on emerging emissive technologies (e.g., QDs, lasers). Masaoka anticipated a transition period where displays would gradually approach Rec.2020 – not an indefinite “container-only” phase. This directly refutes claims that it was intended solely as an interchange container. Rec.2020 was explicitly designed as a mastering color space, not merely a container.
No Display 2020 Compliant
“The ITU has ratified the UHD Phase 1 specification, which includes the 2020 color gamut. The specification calls out the red, green and blue primary wavelengths, but it does not give any tolerances. Since these are located on the spectral locus, only laser sources can produce the full color gamut – but with speckle, which is unacceptable. To fix the speckle means the primaries are no longer pure. What’s the result? No display can claim to be “compliant” to the 2020 specification.” – The Status of Wide Color Gamut UHD-TVs
Rec.2020 Disagreeable
It’s not only industry consultants who are opposed to Rec.2020. Colorists also find colors beyond P3 objectionable.
“To be honest, the full gamut of [BT.]2020, I don’t think we’re ever going to see it. 95% of the Pointer’s gamut, which covers most of the naturally reflected colors in nature – trees, fruits, skin tones and everything – it’s about P3, it’s slightly larger than P3. Those primaries of [BT.]2020 gamut and with tone mapping and 10,000 nit… you don’t achieve that. It’s unachievable. A green laser: are we gonna really talk about the artistic intent of a green laser in the background in some fireworks or something like this? I don’t think so. […] I would consider to all this paranoia of “No, we want the [BT.]2020, we want to do it fully,” and so on – no you don’t. What you need to do is as good as you can, at least P3. Go in a little bit of the boundaries of P3-D65, that’s totally fine. But that’s what you really want to do, because that’s what the people getting at home in the best cases, that’s what a consumer TV can do. Even the 30K monitors that we have, they don’t do all the [BT.]2020, it’s impossible. I have a projector here in the cinema that does the green primary of [BT.]2020 and you cannot imagine how fluorescent that is. It’s just unreal.” – Pablo Garcia Soriano, Colour Supervisor, Managing Director, CROMORAMA
When asked why DCI, a consortium of major motion picture studios, specified P3 primaries rather than BT.2020 in their DCI High Dynamic Range D-Cinema Addendum, they replied:
“DCI had to weigh the creative value of BT.2020. We’ve worked closely with colorists in attempts to demonstrate the value of colors outside of DCI-P3, and those attempts have been far from compelling. In general, colorists prefer to reduce color saturation. This isn’t entirely without exception, of course, as there have been some notable examples of studios utilizing color values far outside of DCI-P3 but they’re extremely limited. For example, Pixar, in a single shot in the movie “Inside Out”, notably opted for a green value well outside of DCI-P3 to depict broccoli. Nonetheless it’s been difficult to make a compelling case for the real creative value there. So, given all the challenges to achieve 100% BT.2020, the lack of any standard that describes a realistic subset of BT.2020, and the doubtful creative value, DCI opted to retain DCI-P3 as the color gamut for the D-Cinema HDR specification/standard.”
Poor Performance of Rec.2020 Gamut Mapping
Content mastered in Rec.2020 must be gamut mapped for consumer displays that don’t support such a wide gamut, which can have serious consequences in terms of image quality. In their paper Color-gamut mapping in the non-uniform CIE-1931 space with perceptual hue fidelity constraints for SMPTE ST.2094-40 standard, Chang Su, Li Tao and Yeong Taeg Kim argue that, while conventional gamut mapping techniques work well enough for projects constrained to the P3 gamut, those mastered in Rec.2020 can exhibit serious artifacts, “including detail loss, hue distortions, even high visual impacts such as banding, alien color spots, etc., thus seriously degrading the final visual quality.”
Metamerism
“Various studies pointed out that narrow-band primary displays would increase the possibility of metameric failures, and it can be a severe issue in color critical applications, for example, color grading. As HDR displays are ultimately expected to cover the full extent of Rec.2020 color gamut, it is inevitable for such displays to use extremely spectrally narrow light sources or color filters and/or adding more primaries. Therefore, it is not surprising that OM is regarded as a potential issue of HDR displays.” Effect of color gamut and luminance on observer metamerism in HDR displays, Yongmin Park, Facebook Reality Labs, Michael J. Murdoch, Rochester Institute of Technology (November 2020)
“[D]isplay systems with narrow-band primaries have significantly greater potential for observer metamarism. Thus, despite their potential for other benefits, display manufacturers might want to consider forgoing the use of narrow-band primaries for displays in color-critical applications.” Mean Observer Metamerism and the Selection of Display Primaries. Mark D. Fairchild and David R. Wyble, Rochester Institute of Technology, Munsell Color Science Laboratory, Rochester, NY/USA
“Human vision has developed to work with the broadband power spectrum of white light from the sun, so viewing narrow primaries can cause color perception errors (or variation) when viewing sources with the finely tuned power spectrums from systems designed to approach Rec. 2020.” Conference Features Advances in WCG, HDR, and 3D. Bob Raikes
Resource Hungry
Italian tech website DDay.it contributor Paolo Centofanti attended a presentation by TCL Europe in Warsaw in November 2023 where the manufacturer showcased their newest lineup of 85″ and 98″ miniLED TVs, which are claimed to cover as much as 90% of the BT.2020 color space. Interestingly, TCL doesn’t consider 100% BT.2020 all-important, at least not for the time being. Centofanti wrote,
“The Rec.2020 gamut race, which, like the one for the 8K, TCL does not consider a priority at the moment, basically for the same reasons: lack of content that makes wide use of it, difficulties for consumers to perceive its benefits, substantial impact on energy performance. With RGB OLED and Micro LED things might change, but it will still take some time.”
Concerning the impact BT.2020 has on energy consumption, Mike Hack, VP, Business Development, Universal Display, presented a paper at Display Week 2021, where the authors calculated the change in power consumption of a display going from sRGB to DCI-P3 to BT.2020. In the study, the simulated OLED display consumed ~2300 mW for sRGB, ~2450 mW for DCIP3 and ~3000mW for BT2020, while the power consumption of an LCD was even greater.
The Daejeon Chronicles 