To read about our monitor tests in-depth, check out Display Testing Explained: How We Test PC Monitors. We cover brightness and contrast testing on page two.
Uncalibrated – Maximum Backlight Level
We dug deep into our database to find 4K 144Hz monitors to compare the XG27UQ’s performance. It turns out only Asus and Acer have screens that boast these two specs, as well as the XG27UQ's DisplayHDR 400 or better and Adaptive-Sync. We have the two standard-bearing screens, the Acer Predator X27 and Asus ROG Swift PG27UQ, along with the Acer Nitro XB273K and Acer Nitro XV273K. The Asus ROG Strix XG279Q is a 1440p resolution screen that tops out at 170 Hz but delivers everything else the 4K monitors do.
With over 427 nits available in SDR mode, the XG27UQ is more than bright enough for any environment. Even a covered outdoor space would be fine. The backlight has a 100-step adjustment and bottoms out at 56 nits, which is nearly ideal when the room is otherwise free of light. Black levels and contrast are typical of the average IPS panel at just over 1,000:1. This can be enhanced to just over 3,000:1 by engaging the Dynamic Dimming option. We normally don’t recommend dynamic contrast features as they tend to clip highlight and shadow detail, but this one worked well.
After Calibration to 200 nits
After calibration (see our recommended settings on page 1), black levels and contrast remained mid-pack with a solid 1,057.2:1 score. Whether you calibrate or not, Dynamic Dimming is an effective way to increase image depth and make blacks truer without sacrificing detail.
Our XG27UQ sample had a couple of uniformity issues that lowered the ANSI score. These were seen in the corners of the screen so content in the other zones has a satisfying level of contrast and saturation.