The XB273K carries VESA’s DisplayHDR 400 certification, which means it will surpass 400 nits peak brightness with HDR material. It does this easily and delivers excellent black levels and contrast while doing so.
HDR Brightness & Contrast
At just over 469 nits, there is plenty of headroom to ensure well-detailed HDR content with bright highlights and deep shadows. Effective contrast is an excellent 4,104.1:1, which puts the monitor in the company of good VA panels. It won’t hit the lofty numbers of the full-array backlight monitors, but that is something you have to sacrifice to save around $500 (£400).
Among rank-and-file HDR monitors, the XB273K is one of the best.
Grayscale, EOTF & Color
Since there are no adjustments available for HDR signals, it’s a good thing that Acer did its homework before tuning the XB273K. Grayscale tracking is essentially perfect with a tiny bit of visible blue tint at the 65 percent clip point. After that, whites are a bit warm, but this is a minor issue that won’t impact gaming or video enjoyment one bit.
Luminance tracking is also within a whisker of perfect, with just a slight soft-clip at around 60 percent brightness. This level of accuracy ensures maximum depth and contrast for HDR material.
When tracking the DCI-P3 gamut in HDR mode, the XB273K goes for a bit of extra saturation in all of the primary colors. While not perfectly accurate, it adds a nice bit of extra punch to games and video. The magenta is slightly off hue as well. Again, however, these are small errors and well within the reaches of acceptability.
We consider this display to be reference-level for HDR content.
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