Our HDR benchmarking uses Portrait Displays’ Calman software. To learn about our HDR testing, see our breakdown of how we test PC monitors.
The GP27Q delivers superb HDR quality thanks to its 576-zone Mini LED backlight. Apart from an OLED, no monitor will compare. Just remember to switch HDR to Auto the first time you fire it up. Then it will go back and forth without user intervention.
HDR Brightness and Contrast
The GP27Q easily beats its claimed 1,200-nit spec with full field and window patterns. To get this much output for $550 is a real breakthrough for Mini LED.
I could not measure black levels even when I displayed a small object near the meter’s sensor. The GP27Q uses its zone dimming to excellent effect. This is about as close as an LCD panel can get to matching the depth and dynamics of an OLED. For these tests, I set the HDR mode to User with full brightness and local dimming on low. If you turn off local dimming, the HDR contrast ratio is around 900:1.
Grayscale, EOTF and Color
I was disappointed to see that there are no color temp adjustments possible in HDR mode. The GP27Q runs fairly cool in the brighter areas of the image. This is slightly mitigated by the super saturated color, but a warmer white point would make the picture even better. Luckily, the EOTF closely follows the reference with slightly dark shadows and a tiny rise below the tone-map transition. These are very minor errors that can’t be seen in actual content.
You can see in both HDR gamut charts that the blue white point pulls both cyan and magenta off their hue targets. Saturation is very good for all colors, with a linear progression from bottom to top. And since the GP27Q covers most of Rec.2020, you’ll see HDR content the way its creators intended. While these test results could be improved upon, the HDR quality is well above all but the very best premium monitors. And don’t forget that the GP27Q costs just $550.
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