To learn about our HDR testing, see our breakdown of how we test PC monitors.
Applying an HDR10 signal to the XG27UQ puts it in HDR mode automatically. All image controls are locked out, and you get two HDR-specific modes, Gaming and Cinema. As you’ll see, they are quite close in appearance and accuracy.
HDR Brightness and Contrast
Starting with the contrast tests, the XG27UQ proves capable of its DisplayHDR 400 certification with over 463 nits peak white. Only the X27 and PG27UQ are significantly brighter by virtue of their 1,000-nit full-array local dimming (FALD). You'll have to pay almost double the price for FALD. With Dynamic Dimming locked to the on position, the XG27UQ delivered a very low HDR black level. We had a hard telling if the monitor was still powered on when viewing a black field pattern in a moderately lit room. Resulting contrast is an excellent 8,216.40:1. We measured identical results in both Gaming and Cinema HDR modes.
You can see that the XG279Q has a more aggressive dynamic feature, and the two FALD screens with their 384 dimming zones are on another level. For this price though, there isn’t much better HDR than that delivered by the XG27UQ.
Grayscale, EOTF and Color
All Asus HDR monitors offer two HDR-specific modes, Gaming and Cinema. Sometimes the difference is easy to spot, but with the XG27UQ, we could barely tell them apart, and the measurements bear that out. Grayscale accuracy is virtually the same with a slight purple tint visible in the brightest steps. The EOTF luminance curves are also similar with a slightly softer transition shown in the Cinema chart. With no difference in either color or contrast, we stuck with the default Gaming HDR mode for our hands-on tests.