Brightness And 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.
Uncalibrated – Maximum Backlight Level
The Z27q is clearly aimed at professional users with its factory calibration and premium technology. Therefore, our comparison group is made up of equally credible displays. From NEC we have the PA272W, a Tom's Elite Award winner, and the PA322UHD. BenQ is represented by the SW2700PT, also a recipient of our top Editor’s Choice Award. From Asus is the recently-reviewed PA328Q and HP’s other premium display, the Z27x which won the Tom’s Elite Award last year.
Most pros don't need a lot of output since they typically work in a darkened space. Even though we set 200cd/m2 as a practical brightness level, 120 is more common. That being said, the Z27q gives up a little power to its competition, but still meets the claimed 300cd/m2 specification.
Black levels at the max backlight setting are a little disappointing but still perfectly acceptable for the work this display is designed for.
The Z27q's contrast comes up a little short of our 1000:1 preference. It does however beat out the Asus PB328Q. This is still well within the realm of typical performance for an IPS monitor, regardless of resolution, which seems to have no effect on contrast.
Uncalibrated – Minimum Backlight Level
The minimum backlight setting results in an almost perfect 51.7917cd/m2. We wouldn't choose to set a monitor below 50 even with all the room lights off simply because it causes unnecessary eyestrain. If you're looking for the in-between brightness levels please refer to the bottom of the previous page where we've provided some suggested settings.
Contrast is consistent throughout the Z27q's brightness range so this black level result is expected. The only way to achieve significantly better performance here is with a VA panel. Remember that the top-finishing SW2700PT is AHVA, which is a variation of IPS; not to be confused with AMVA.
The minimum contrast number is only two percent lower, which is a negligible amount. The Z27q's consistency is equal to any other professional screen we've tested.
After Calibration To 200cd/m2
We calibrated the Custom RGB mode for the next series of tests. While it didn't improve its ranking for black level it did offer a tiny bit more contrast, as you'll see in the next chart.
938.4 is still below our favored 1000:1 level but at this point we can't complain about the Z27q's image depth or quality. It's still one of the richest pictures we've seen thanks to impressive pixel density. Even though it gives up a little contrast performance, it's worth the gain in resolution in our opinion.
ANSI Contrast Ratio
Hotspots in the upper left and lower right zones of the screen spoil the ANSI result somewhat. 777.1:1 is still a decent measurement but with a little better uniformity it would have been higher. You'll see later though that there is no light bleed to be seen and overall field uniformity is still within acceptable limits.