One of the selling points of Dell's new U2518D monitor (opens in new tab) is that it offers HDR support for presumably brighter and better looking visuals, though some are chalking it up as a marketing ploy. The reason is because it is not capable of delivering a true HDR experience.
The 25-inch display is the first from Dell to list "Dell HDR" in the spec sheet. At $500, it seems like a decent deal—after all, it also features a 60Hz in-plane switching (IPS) panel with a 2560x1440 resolution and thin bezels, a feature Dell calls "InfinityEdge." It's when you look closer at the specs that Dell opens itself up to scrutiny.
The U2518D uses an 8-bit panel, whereas the official HDR10 spec (opens in new tab) and accompanying HDR10 Media Profile calls for a 10-bit panel. And while Dell lists 99 percent coverage of the sRGB color space, the monitor's maximum brightness of 350 nits is unusually low for an HDR display.
As pointed out by Guru3D (opens in new tab), the simulated software-based HDR mode that responds to HDR10 content on Dell's display falls short of the color gamut, peak luminance, and bit-depth that is necessary true HDR.
We have not spent any time with the U2518D ourselves, though the folks at TomsHardware reviewed the larger 27-inch model (S2718D).
"It’s clear from our test results that the S2718D does not break new ground in the area of contrast. It lacks the light output to truly present the full dynamic range of HDR, nor does it have sufficiently low black levels," TomsHardware notes (opens in new tab). "Dell pre-empts this by stating in the manual, 'HDR: Adapted High Dynamic Range appropriate for monitor usage.' Obviously, a contrast ratio below 1000:1 won’t truly cut it."
That said, the review found that Dell's monitor does properly track luminance to HDR10 and delivers an "excellent movie-watching experience." Nevertheless, if it's true HDR support you're looking for, you'll want to look for one that specifically says it's capable of HDR10 (or Dolby Vision) and avoid marketing non-standard marketing labels.