DisplayHDR True Black: what the OLED tiers ask for
By TechCompare · Updated · How we check
Every True Black tier caps black at 0.0005 nits and asks for a rise to peak within 2 frames. In return, they ask for less on a full screen: True Black 400 needs 250 nits on a flash where DisplayHDR 400 needs 400.
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| Test | DisplayHDR 400 | DisplayHDR True Black 400 |
|---|---|---|
| Peak brightness (8% patch)The brightness a small highlight has to reach. It's the number in the tier's name. | 400 nits | 400 nits |
| Full screen, flashHow bright the whole screen has to get for a moment, like an explosion in a game. | 400 nits | 250 nits (differs) |
| Full screen, longHow bright the whole screen has to stay for a long time, like a bright sky or a white page. | 320 nits | 250 nits (differs) |
| Black level, highest allowedHow dark the middle of the screen has to stay while two corners show full white. Lower is better. | 0.4 nits | 0.0005 nits (differs) |
| BT.709 coverageHow much of the normal SDR color range the screen has to cover. | 99% | 99% |
| DCI-P3 coverageHow much of the wider DCI-P3 color range, the one HDR movies and games use, the screen has to cover. | 90% | 95% (differs) |
| 10-bit input signalThe screen has to accept a 10-bit signal, which HDR10 needs. | Required | Required |
| Rise time, black to peakHow many frames the screen can take to go from black to full brightness. Fewer is faster. | 8 frames | 2 frames (differs) |
| Static contrast, one imageThe contrast within one image, black and white on screen at the same time. True Black tiers don't have this test, and their black level limit is far lower. | 1,300:1 | Not tested (differs) |
| What it takes for contrastVESA's own summary of what the contrast test asks of an LCD. | High native contrast or 1D local dimming | Not tested (differs) |
Values in white differ between the two tiers. Minimums from VESA DisplayHDR performance criteria, CTS 1.2.
The True Black tiers are meant for screens that light each pixel on their own, like OLED. They keep the brightness number, so True Black 400 and DisplayHDR 400 share the same peak, but the rest of the rules are built for a different kind of panel. The table puts True Black 400 next to DisplayHDR 400 under CTS 1.2.
How this is calculated
Black is the headline. DisplayHDR 400 allows 0.4 nits with white in two corners, while every True Black tier allows 0.0005 nits. True Black also has a test the classic tiers don't: black has to stay at 0.0005 nits in a checkerboard of full white and black, which an LCD's backlight can't do.
Speed is the second change. The classic tiers can take 8 frames to go from black to peak, and the True Black tiers have to do it within 2. Self lit pixels switch fast, so it's an easy rule for OLED and a hard one for a dimming backlight.
Full screen brightness goes the other way. True Black 400 asks for 250 nits on a full screen, both on a flash and held for a long time. DisplayHDR 400 asks for 400 on the flash and 320 held. OLED panels limit how much light they put out at once, and VESA's numbers allow for it.
Some rows don't apply. The True Black tiers have no static contrast test, no active dimming test and no backlight control test, since there's no backlight. CTS 1.2 has five True Black tiers, up to True Black 1400. CTS 1.1 stopped at True Black 600.
Verdict
True Black is the label to look for if deep blacks matter most, like dark room movies and games. Don't read the number as if it were a classic tier. A True Black 400 screen can look far better in dark scenes than a DisplayHDR 400 one, but dimmer in bright full screen scenes.
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Frequently asked questions
Is DisplayHDR True Black only for OLED?
Is True Black 400 better than DisplayHDR 600?
Why is True Black full screen brightness so low?
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