Applying an HDR10 signal switches the PG279QM to HDR mode automatically. There are no additional picture modes available, but you can still access the same presets as SDR as well as adjust contrast and color temperature.
HDR Brightness and Contrast
The PG279QM is a DisplayHDR 400 monitor, and it tops 423 nits as expected. Though there are brighter monitors here, the more important metrics are contrast and black levels. There, the PG279QM takes the prize by a large margin, thanks to its zone dimming feature. It isn’t quite as dramatic as a full-array backlight but by modulating the edge array, the PG279QM can achieve excellent HDR contrast and image depth.
Grayscale, EOTF and Color
I couldn’t create an independent HDR calibration, but the settings I used in SDR mode worked well for HDR. There is a slight coolness in the brightest steps, but that error is hard to spot in content. The EOTF starts off too dark because of the zone dimming but rises to meet the spec with a hard transition at 65% brightness. Some shadow detail can be hard to see depending on the game or video you’re viewing, but in general, the PG279QM delivers superb HDR.
I checked both DCI-P3 and Rec.2020 gamuts for HDR and found the PG279QM maintained the correct hues for each. Inner color targets are 5-10% oversaturated which is not enough to cause a problem. If you’re viewing HDR material mastered to DCI-P3, it will render accurately. If it’s encoded to Rec.2020, it will also be accurate until the highest saturation levels where color runs out. But with only a 20% volume deficiency, the PG279QM will still outshine nearly any other monitor regarding color saturation.