„For Those Who Dare“

Electronics supermarkets for general audiences are offering calibration of TVs as an option now, and some gaming monitors will even bring along an individual calibration chart.This is part 4 of our color monitoring series (it started here).

TV and cinema

Well, according to our recent measurements, the decently priced ProArt models by Asus can suffice for Rec. 709 and even some more. We were quite surprised finding a wide QHD gaming monitor by Xiaomi also coming with a chart and meeting the specs when checked with our probes and software. But then, this all applies to screens which can meet Rec. 709 without much effort. While professional grading for cinema in DCI P3 would normally be done in a dark room with a calibrated projector, what about grading for HDR? 

Well, let’s first get some misconceptions out of the way, since most of the marketing stuff is confusing things (intentionally?). DCI P3 would be the standard for cinema, as explained above. It expects a gamma of 2,6, but only 48 nits for white – after all, it’s for a dark environment and a very large screen. You may not even notice in cinema that it has a white point around 6.300 K, which is better suited to Xenon lamps. You would not really like to watch that it in a living room or, even worse, outdoors. 

So, Apple created a thing now called Display P3. This has never really been standardised, but has been adopted by others, mainly for phones and tablets. So, a majority out there might be able to watch video like that now instead of the older Rec. 709 for TV. The white point is 6.500, standard white is 120 nit, and gamma is 2.2. The only thing it has in common with cinema is the wider color space of P3. While Rec. 709 (or sRGB) is only covering about one third of human vision for color (as defined by CIE 1931), P3 is doing more than half. And Rec. 2020?

Rec. 2020, a standard for the future

The color space for HDR TV in the foreseeable future is defined by Rec. 2020. It would cover 75% of human vision for colors, but very few technologies of today can reproduce it. RGB pure laser projectors can achieve up to 98% of the Rec. 2020 color space, and one from Christie will cost you only 84.000 € (plus tax and lens). It will eat 1.800 watts of power and resolve HD natively, but simulate more by pixel-shift (see more here at Christie’s).

Oh, and one of those is normally used for presentations in special venues, like theme parks, projection mapping, IMAX, and impressive exhibitions, not in your average local cinema. Anyway, some cinemas are going for them now for attraction and future proofing. If we are trying to get more realistic, we will look at ordinary monitors, the best of which may cover 86% of that color space. 

Technologies to get there as of today are WOLED, QD-OLED and mini-LED, to which Apple recently added Tandem-LED in the iPad Pro – as usual, without telling us the exact percentage of Rec. 2020 achieved. For some realism, read this. BTW, even a huge QD-LED based reference monitor from Flanders Scientific, a manufacturer respected by professional colorists, the XMP551, will cost you around 20.000 € and covers ‚only‘ 90% of Rec. 2020 color gamut.

What about HDR?

HDR, though, is mainly about contrast. Generally, you could increase contrast by stronger highlights, which is driving up power consumption and heat, or by deeper blacks. OLED is one of the technologies getting pitch black, other than conventional LCD screens. It also has very wide viewing angles without any image degradation. Unfortunately, OLED has a hard time with very high brightness, which may ruin it quickly without protective measures. What’s on the market right now?

Flanders XMP310 and XMP270 both can handle 1.000 nit for Dolby Vision, which is only one of the competing standards, and reach ’only’ 80% of the 2020 color gamut. But even these are well beyond 10.000 €. Apple claims 1.600 nit for their XDR screens. While these are still expensive in larger sizes, they come for less in mobile devices. But all such maximum values are for local highlights. If it would show that full screen, the poor thing would go up in flames. 

So, to protect the OLED, all of such displays use an ABL (auto brightness limiter), just like LG OLED TVs, which are also popular with pro colorists. In consequence, all of them will be able to show highlights to a varying degree of brightness, but only in a limited area. Even the expensive Flanders have ABL, and you can only switch that off by going deep into hidden service menus and ruining your warranty. Ouch! 

For any such screen, the maximum brightness achieved will be related to the percentage of screen estate that highlights are covering, and normally there’s even a difference between peak values displayed for a short time and sustained ones. Of course, any decent screen will sustain more than 120 nits on the whole screen, so it should not be a surprise if we calibrate to 120 even for HDR. What comes as a bad surprise are changes in the whole scene when ABL kicks in. So, what to choose?

We may see Apples Tandem-LED screens in future MacBooks, but I doubt any time soon in larger monitors. Under the current iPadOS you can can’t calibrate an iPad. In the end, we had a closer look at an OLED screen for gamers, the Asus PG27AQDP. It comes calibrated for SDR with an individual chart from the factory. Getting up to 600 nit and covering P3 would already give you a decent HDR look with perfect blacks. It’s not a QD-OLED, but didn’t I start with the slogan „Color Grading for Cheapskates“?

Measuring an OLED monitor

At first view, it’s very obviously targeted at hardcore gaming, being part of the „ROG“ (republic of gamers) product family. The headline we cited above also aims at that community. Nevertheless, it comes with an individual chart, surprisingly made for Rec. 709 (actually, sRGB), with a gamma of 2,24 and an average color accuracy of 1,37 Delta-E, not exceeding 2,1. It carries the DisplayHDR True Black 400 label, which is an independent label by VESA, even if the lowest level (screens with higher ones are considerably more expensive). For details, see here.

Of course, we did not want to trust just the chart or label alone, and also see what we get for the newer standards. Older probes like our trusted Color Munki or X-rite (see here) can’t handle OLEDs correctly. If you’d try the approach described in my other articles, you’d be disappointed. At first view, the values look really bad. That’s not a limitation of the screen, but those older probes are not ready for recent technologies. 

This time, we got a Spyder Pro by Datacolor (more about it in another article), which is capable of taking on OLED and very wide gamut, and handling up to 2000 nits. It is not recognised by DisplayCal, so we used the Software coming with the probe, aptly named SpyderPro, in version 6.2.

Adjustments

The software is pretty easy to operate and fast. As described in our articles linked above, one should first try to get the screen as close to specs as possible with its internal adjustments. While the color adjustments didn’t help much, at least you can turn down the brightness to the levels needed according to standards.

But we observed a strange phenomenon here: brightness always went up a bit when leaving the OSD. So, you’ll need a bit of fiddling to get it right, we ended up with a value of 42 in the OSD (for HDTV). There might be some ABL switching on and off even at these levels.

Another confusion resulted when checking the gamma: while the OSD is offering choices of gamma values, it’s always far too high, according to the Spyder Pro. We needed the lowest setting of 1.8 to meet the standard for web at 2.2, and the next value to get 2.4 for proper BT. 1886. These deviations may be corrected by Asus with firmware upgrades, but their installer didn’t work for us.

Since we didn’t get any better results from trying to adjust colors, we decided to try the presets offered by the monitor’s menu. BTW, all of these adjustments are available in performance mode only, in energy saving mode you’ll be stuck in gaming settings, for whatever reason. 

Results

Once we got brightness and gamma right, the results were not bad at all. Rec. 709 is fully covered, and P3 to 96%, which you’d hard pressed to tell from 100% visually. Rec. 2020 colours are covered to 71%, but check above how much you’d pay even to get 80. For the time being, stick to P3 for HDR. Brightness peaks close to 1.200 nits, but only for a tiny area of 2% of the screen. 

For comparison: Apple doesn’t tell us how much their Liquid XDR with Mini-LEDs in the recent MacBook Pro can cover at 1.600. While Rtings measured less than 1.500 for 2%, it can sustain close to 1.200 even for the full screen. The color gamut is full P3 and close to 73% of Rec. 2020 ( see here). Its only weakness is some blooming, and, of course, the size.

Nevertheless, you can get over 600 for 10% of the Asus screen, which is decent for practical work in HDR. Contrast ratio is, of course, kind of infinite, since black is black. One big advantage over Mini-LEDs is the absence of blooming. The screen offers detailed features to fight burn-in, the achilles heel of OLED. This may be even more important than for games if you have one single GUI like DaVinci Resolve on the screen all day long. Asus says they are using a custom heatsink to get such bright highlights.

The software by Datacolor comes with a separate app for analysis of a screens quality, called Spyder MQA. Compared to factory calibration by Asus, most of the skin tones and lighter gray values got improved by the Spyder’s calibration, while one dark cyan (1F) suffered, even into slightly visible deviation. All other patches stayed under 3 or only a tiny bit over, with an average close to 2.

Datacolor explained this one deviation at 1F by the difficulty to calibrate a monitor with very wide native colors to Rec. 709 or even P3. Without a high-end probe around, we can’t verify this, but it seems plausible. If trade-offs are unavoidable, it makes perfect sense to go for good skin tones and a neutral greyscale. While some uniformity issues for brightness are normal at this price level, color uniformity is excellent, being under 2 Delta-E at 100% brightness.

Handling

Mechanics of the PG27AQDP leave a few points to be desired. Proper horizontal alignment is difficult to find, there is no fixed position for it and the adjustment shows a lot of friction. The height adjustment simply didn’t hold for us, always returning to the top position. Reviewing only one sample, we can’t tell if this is a problem with our unit only, but I’d assume it is. 

And then, the support with its three legs is prone to let it fall off the table when there is no wall behind and it’s pushed back too far. The ProArt PA279CV doesn’t have such issues and is coming with a heavy, rectangular plate. While the gaming screen looks stylish, you ask yourself how it gained two design awards – form follows function doesn’t matter any more? Even gamers complain about the space blocked by those legs in the front.

Service

The chatbot for support is not the brightest candle, a very specific question about a ProArt PA279CV being compatible with Asus’ Display Widget Center was answered with standard marketing information, not meeting the point. But you may download very detailed manuals as PDF in several languages. Our experience with their serve center in Germany when needing repair for a ProArt PA279CV about two years old with broken backlight was excellent. No, we didn’t inform them about reviewing it, but appeared as a regular private user.

Recommendation

While you can’t get the PG27AQDP for the price of a Xiaomi G34WQi or an Asus ProArt PA279CV, which are decent for SDR, it is one of the best low-cost options for HDR. Small highlights pop in HDR, but aggressive ABL can kick in. For those who also need to grade for SDR, it’s also fine with a separate calibration. 

If you are not into hardcore gaming too, you can get the very similar Asus XG27AQDMG with a lower refresh rate for less. It’s also VESA HDR 400 approved, but glossy. So, the choice also depends on your environment, since the PG27AQDP is matte and has a bit less punch. Definitely look for that minimum VESA label, including the True Black notion, since everybody is calling their screens HDR these days, without any proper justification.

We also had an issue with fine text. It is a bit rough and less readable than on the Xiaomi G34WQi, which has the same vertical resolution. A different sub pixel layout seems to be the cause. But that doesn’t matter if you use it strictly for monitoring your final video and have another monitor for the GUI, where many prefer a wider screen anyway.

Specs of the Asus PG27AQDP OLED

Resolution: 2560 × 1440 (QHD)
Aspect Ratio: 16:9 @ROG+6@ROG+6@ROG+6
Panel Type: WOLED (3rd‑gen OLED + MLA lens array)
Pixel Pitch: 0.229 mm
Display Colors: True 10‑bit (1.07 billion colors)
Color Gamut: 99 % DCI‑P3, 135 % sRGB
Contrast Ratio: 1,500,000 :1 typical
Viewing Angle: 178° horizontal, 178° vertical
Surface Finish: Anti‑glare
Standard Max Brightness: 450 cd/m² (nits) @ROG+9@ROG+9@ROG+9
Peak HDR Brightness: 1,300 cd/m² (3 % APL) @ROG+4@ROG+4@ROG+4
Contrast: OLED-level true blacks @ROG
HDR Format: HDR10, VESA DisplayHDR True Black 400 certified
Refresh Rate: Native 480 Hz @ROG+2@ROG+2@ROG+2
Response Time: 0.03 ms gray‑to‑gray
Adaptive Sync: NVIDIA G‑SYNC Compatible, AMD FreeSync Premium
Flicker: OLED Anti‑Flicker technology
Factory Calibration: ΔE < 2 (average)
User Calibration: Supported via DisplayWidget Center
Burn-In Management: ASUS OLED Care+ functions (pixel cleaning, screen saver, pixel shift, logo dimming)
Display Inputs: DisplayPort 1.4 (w/ DSC), HDMI 2.1
Uniform Brightness Mode (limits ABL)

All Specs are here at the Asus Site