Is DisplayHDR 400 real HDR? What the entry tier asks for
By TechCompare · Updated · How we check
DisplayHDR 400 is tested, so it's real in that sense, but it's a light version of HDR. Its black level limit of 0.4 nits and a static contrast minimum of 1,300:1 can be met without local dimming, so dark scenes look much like SDR.
Calculator
| Test | DisplayHDR 400 | DisplayHDR 1000 |
|---|---|---|
| Peak brightness (8% patch)The brightness a small highlight has to reach. It's the number in the tier's name. | 400 nits | 1,000 nits (differs) |
| Full screen, flashHow bright the whole screen has to get for a moment, like an explosion in a game. | 400 nits | 1,000 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 | 600 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 | 0.05 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 | 8 frames |
| 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 | 30,000:1 (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 | 2D local dimming or better (differs) |
Values in white differ between the two tiers. Minimums from VESA DisplayHDR performance criteria, CTS 1.2.
DisplayHDR 400 is the entry tier of VESA's HDR certification. It means a monitor takes an HDR signal, reaches 400 nits on a small patch and meets a set of color and speed rules. Whether that's real HDR depends on what you expect HDR to do. The table puts its CTS 1.2 minimums next to DisplayHDR 1000.
How this is calculated
Under CTS 1.2, DisplayHDR 400 asks for 400 nits on an 8% patch and on a full screen flash, and 320 nits on a full screen held for a long time. Black has to stay at 0.4 nits or less with white in two corners. The screen has to cover 99% of BT.709 and 90% of DCI-P3, accept a 10-bit signal and reach its peak within 8 frames.
What it doesn't ask for is the part that makes HDR stand out on better screens: deep black right next to a bright highlight. VESA's own note says DisplayHDR 400 passes the contrast test with high native contrast or 1D local dimming. VESA's FAQ says local dimming isn't required by the spec at the 400 level. So an edge lit monitor with one backlight level for the whole picture can carry the logo, which means a highlight brightens the dark parts of the frame too.
Under CTS 1.1 the bar was lower. DisplayHDR 400 needed 95% of BT.709 and had no DCI-P3 minimum, so a monitor certified then can have plain SDR color. VESA's FAQ says a certification doesn't expire, and those monitors are still sold with the same logo.
True Black 400 is a different case. It shares the 400 number but caps black at 0.0005 nits, which takes a screen that can switch pixels off, like OLED. If the box says True Black, you get the deep blacks.
Verdict
DisplayHDR 400 tells you a monitor takes HDR and won't be dim, but it doesn't promise the contrast that makes HDR look different from SDR. If HDR games and movies matter to you, look for DisplayHDR 600 or higher, or a True Black tier. On a monitor you already own, the HDR Test shows what it does.
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Frequently asked questions
Is DisplayHDR 400 worth turning on?
Is HDR400 the same as DisplayHDR 400?
Does DisplayHDR 400 need local dimming?
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