The XG43UQ switched automatically to HDR mode when an HDR10 signal is input. Three picture modes are offered but we couldn’t detect any difference between them. All our test results showed the HDR Game mode which is the default.
HDR Brightness and Contrast
The XG43UQ is rated for 1000 nits but we came up a tad short of that mark. We measured both window and full field patterns and got the same result. This isn’t a deal breaker, since 975 nits is still searingly bright. It is possible other samples will measure differently.
The black level proved difficult to measure. A full black pattern resulted in complete shutoff of the backlight making measurement impossible. By displaying a small info bug at the bottom of the screen, we were able to measure 0.0549 nit for a contrast ratio of 17,755.3:1. This is with Dynamic Dimming engaged. If you turn that off, the HDR contrast ratio is 4,356.8:1. This is a good result, but the other panels produced deeper blacks.
Grayscale, EOTF and Color
The XG43UQ’s HDR mode is very color accurate. Grayscale tracking is visually perfect with no errors seen at any point. The tone-map transition is at a very high 75% which demonstrates the panel’s ample brightness. HDR black levels start out a bit low but not low enough to obscure shadow detail. There is a slight hump before the transition point, but this could not be seen in content. Overall performance in the HDR grayscale and luminance test is excellent.
The XG43UQ also tracks HDR color very well. Like most HDR screens we’ve reviewed, inner targets are over-saturated but linear which means all the detail is visible. Color is rich and vibrant with lots of depth and natural hues. Green comes up short at 100% saturation but hits the inner targets which means textures like grass and trees will look very lush. This is excellent performance.