To see the best HDR quality possible, a monitor needs two things: wide dynamic range and the ability to address the brightness of each pixel in the array on a frame-by-frame basis. LCD monitors can approximate this with zone dimming, but even the latest Mini LED screen can’t compete with an OLED panel that can manipulate every one of its 8.3 megapixels. The FO48U may not be as bright as an LCD, but its HDR is on another level entirely.
HDR Brightness and Contrast
The FO48U is a major step up in brightness from the AW5520QF. As impressed as we are with the Alienware, the Aorus looks much better in HDR mode. With a peak output just under 400 nits, it matches most other HDR computer monitors in brightness. The other screens are 1000 nits or more and deliver great HDR, especially in brightly lit rooms. But the OLED’s black levels are truly something else. We couldn’t measure them, so the FO48U’s contrast is theoretically infinite.
Grayscale, EOTF and Color
We measured all three of the FO48U’s HDR modes to determine the best one for gaming and entertainment. Though they are nearly the same, there are some subtle differences. All have near-perfect grayscale tracking, so comparisons there are a wash. The mode called HDR has a luminance curve that starts a bit too dark, then smoothly transitions to tone-mapping at 65%. The Movie and Game modes are a little lighter in the mid-tones.
In the gamut tests, all three modes are slightly oversaturated in the middle targets. The Game mode hits more of its targets and is the one we ultimately chose, based on real-world observation. All three presets look great, but Game has just a tad more depth, thanks to its more accurate gamut tracking.