Results: Viewing Angles and Uniformity
The more monitors we test, the more we can see that off-axis viewing performance is dependent not only on pixel structure (IPS, PLS, TN, etc.) but the backlight technology as well. And we can see that the anti-glare layer makes a difference too.
Despite solid performance numbers and its cutting-edge G-Sync technology, Asus' PG278Q still suffers from the poor off-axis image quality inherent to TN-based monitors. The side view is heavily shifted towards red and the luminance is cut in half. From the top, detail holds up a little better than other TN displays we’ve photographed. But image depth is still compromised.
To get the most from this screen, place its center exactly at eye level, tilt it back slightly, and sit about two feet away.
Screen Uniformity: Luminance
To measure screen uniformity, zero and 100-percent full-field patterns are used, and nine points are sampled. First, we establish a baseline measurement at the center of each monitor. Then the surrounding eight points are measured. Their values get expressed as a percentage of the baseline, either above or below. This number gets averaged. It is important to remember that we only test the review sample each vendor sends us. Other examples of the same monitor can measure differently in this metric.
First up is black field uniformity.
Screen uniformity is a bit less consistent with most TN monitors, and our sample does show a little visible light bleed. The problem areas for us are in the upper-right and center zones. You can see the hotspots in a black field pattern, though not in actual content.
Here’s the white field measurement:
The white field pattern looks better, demonstrating a single hotspot in the center. It’s pretty subtle and we could only see it with our i1Pro, not our eyes.
Screen Uniformity: Color
To measure color uniformity, we display an 80-percent white field and measure the Delta E error of the same nine points on the screen. Then we simply subtract the lowest value from the highest to arrive at the result. A smaller number means a display is more uniform. Any value below three means a variation that is invisible to the naked eye.
Color uniformity stays below the visibility threshold with a 2.47 Delta E result. The errors range from 3.01 in the upper-right to a low of .57 in the center.
