Brightness & Contrast
To read about our monitor tests in depth, please check out Display Testing Explained: How We Test Monitors and TVs.Brightness and Contrast testing is covered on page two.
ASUS ROG Swift PG258Q
Uncalibrated – Maximum Backlight Level
There are plenty of high-speed monitors available today but only the Asus PG258Q truly performs on the XB252Q’s level when it comes to gaming. To round out the group, we have AOC’s AG271QG, Acer’s Z301C, ViewSonic’s XG2703-GS, and the sole screen without G-Sync, Monoprice’s MP27 Zero-G. All are capable of at least 144Hz.
The latest G-Sync monitors have truly improved their ULMB implementation by offering high light output. You’ll need that headroom to compensate for the unavoidable brightness reduction caused by a backlight strobe. The XB252Q pumps out 441.7892cd/m2, which is well-above its 400cd/m2 spec. That contributes to a higher black level, but resulting contrast is reasonable at just over 900:1. If dynamic range is your top priority, you’ll need to choose an AMVA panel like the Z301C, which has almost triple the contrast of the next best display.
Uncalibrated – Minimum Backlight Level
106.7008cd/m2 is a bit bright for gaming in the dark, but you could turn on a dim overhead light or use the Blue Light feature to prevent fatigue during long play sessions. That high minimum output contributes to a last place finish in the black level test, but contrast remains consistent at 894.2:1. It seems the IPS panels in the group have a slight advantage in image depth, but AMVA still ranks far above all.
After Calibration to 200cd/m2
ULMB at maximum pulse width only costs about 20% output, which is a good thing. Since the brightness slider is independently adjustable, you can run it up to its maximum for around 320cd/m2, which exceeds many other monitors in their normal modes. The cool part is black levels are lower, which takes contrast to just under 900:1, a 4% advantage. We haven’t seen that before, and it signals a trend of improvement in the technology. ULMB is no longer simply something to add to the feature list. It has become a usable way to reduce motion blur now that it doesn’t require so much compromise in brightness and contrast performance.
ANSI Contrast Ratio
The XB252Q’s ANSI contrast is only a tad lower than its sequential number, which indicates good panel quality. The grid polarizer is fitted precisely, preventing unwanted backlight bleed and hotspotting. Our uniformity tests on page five show that our sample is a solid performer. While this monitor doesn’t have fantastic contrast, it is consistent and reliable.
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