VESA’s new HDR spec makes low-end monitors less miserable

VESA is trying to solve a big problem with its updated DisplayHDR 1.2 specification: Low-end HDR effects in PC monitors can be pretty lousy.

Roland Wooster, a principal engineer for Intel who also chairs the VESA Display Performance Metrics group, described the new update as a “tightening” of the spec, while expanding the scope and criteria of the tests. The goal is to improve the visual quality of the monitors you’ll buy, though one of the tests will also have an impact on how much power they’ll consume, too.

You won’t see the impact right away, however. VESA will preserve the DisplayHDR 1.1 specification and certification until 2025 (and 2026 for laptops) to preserve products that are currently under development.

High-Dynamic Range (HDR) can be an impressive visual effect, mimicking how your eyes adjust to bright lights, especially if you’re emerging from the dark. But displays struggle with preserving dark portions of the screen and maintaining detail in dimly lit scenes.

It’s one reason why we’ve advised you to buy a higher-end DisplayHDR 1000 monitor rather than a cheaper, low-end display. HDR displays come in DisplayHDR 400, 500, 600, 1000, and 1400 specifications, referring to the amount of light in nits that they can produce. You’ll need a GPU and display that can support HDR, plus content that’s optimally encoded for the format.

For more on our display recommendations and why we make them, see our list of the best monitors.

One of the assumptions the new spec tends to make is that you own a MiniLED display. A standard LED display has a single backlight, and raises and lowers the light level across the entire display. OLED displays can essentially turn individual pixels on and off, with infinite contrast. Mini or MicroLED displays are somewhere in the middle: they can have hundreds or thousands of individual LED backlights, known as “local dimming,” that can be used to subdivide areas of the screen. One of the tweaks to the specification is to stop testing two regions of the screen — white and black — and use a “starfield” pattern that actually activates those other local dimming areas.




A test image showing the new “starfield” designed to turn on HDR local dimming zones for a more realistic HDR test.



A test image showing the new “starfield” designed to turn on HDR local dimming zones for a more realistic HDR test.VESA

A test image showing the new “starfield” designed to turn on HDR local dimming zones for a more realistic HDR test.VESA


VESA

What’s new in DisplayHDR 1.2

One of the goals of the updated DisplayHDR 1.2 specification is to bring some of the visual-quality elements associated with more expensive displays down to cheaper price tiers. The color gamut for DisplayHDR 400 is now 99 percent of sRGB and 90 percent of DCI-P3 — essentially the same color gamut as more expensive DisplayHDR 1000 displays currently require. It ups the bit-depth requirement to 8-bit + 2-bit dithering, too.

The difference between SDR and HDR content is, in part, that HDR displays adjust the brightness up and down to produce HDR visual effects. SDR displays don’t. That means that an HDR display has to preserve the color accuracy as the screen lightens and darkens, and DisplayHDR 1.2 dramatically improves the color testing to confirm that accuracy at three difference luminance levels. The updated spec also ensures that an HDR display does a better job with SDR content, so that it doesn’t elevate the black level.

The luminance and white-point accuracy testing range has been expanded, from 1 nit to 100 percent of the tier level — 600 nits for DisplayHDR 600, for example. VESA also added single-image contrast ratio requirements that will effectively improve the contrast ratio and thus the picture, especially for the cheaper DisplayHDR 400, 500, and 600 tiers.

DispayHDR has also added what’s known as a “black crush test,” too. In deeply shadowed areas, some displays will just give up and render the whole scene as a uniform black, rather than preserve the fine, darker detail. (Think of the dimly lit recent movie, The Batman, for example.) The test adds luminance tests at several fractions of a nit to ensure that those details haven’t been “crushed” to a pure black.

Finally, the specification is there to ensure that an HDR display product renders subtitles correctly, managing the backlight and transparency appropriately.

Not every display fails to handle this correctly, Wooster said, “but a few choice ones do. Our goal is to weed them out.”

Monitors