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.
Ultra HD does not affect off-axis viewing performance in the slightest. The PB287Q clearly suffers from the same issues as other TN-based monitors we’ve photographed, though. If you sit closer than 24 inches, as you might be tempted to do given the pixel density, you’ll see color changes at the sides of the screen, even if you are positioned dead-center. Pulling back to 36 inches resolves those anomalies. Obviously, there is a major shift to red at the sides and a loss of detail in the vertical plane.
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 screen. 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.
First up is black field uniformity.
We can see minor hotspots at the center and upper-right portions of the screen in the black field pattern. In actual content, even dark material, we saw no issues.
Our white field pattern looks perfect to the naked eye. A 10.37-percent result is right on the borderline of visibility. Our measurements tell us there’s a dim area in the upper-left corner.
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 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 translates to a variation that you shouldn't be able to see on your own.
A 1.42 Delta E figure is excellent. In fact, it's the best of all 4K screens we've tested. Like the white field uniformity test, we couldn’t see any problems with our press sample. Of this group, only Dell's UP3214Q has any visible color uniformity issues.