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.
Since this is the first AMVA panel we’ve photographed, we have no frame of reference for its off-axis image quality. To us, it looks pretty close to most of the white-LED IPS screens we’ve tested. The light falloff and color shift to green seems consistent whether you view from 45 degrees to the side or from above. Head-on there are no issues, and considering the enormous screen area, that’s a good thing. As I sit writing this, I’m exactly 28 inches away and I can’t see any issues at the edges or corners. If three people sat close to each other, they’d all enjoy a consistent picture.
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.
We mentioned earlier that AMVA technology has a reputation for poor uniformity. Obviously, BenQ and AU Optronics overcame whatever was plaguing previous designs. Our press sample turns in one of the best results we’ve seen. Even if it were higher, the BL3200PT’s low black levels would hide those flaws. To our eyes, it looks perfect.
Here’s the white field measurement:
BenQ's PG2401PT wins this test by virtue of its uniformity compensation look-up table. It’s impressive to see the Overlord screen is only a little behind it. The BL3200PT scores a mid-pack result. However, compared to our entire database, it’s well above-average. Again, our eyes cannot discern any variations in brightness across the screen. For a monitor this large, that’s beyond excellent.
Screen Uniformity: Color
To evaluate 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 a result. Smaller numbers mean a display is more uniform. Any value below three translates to a variation that is invisible to the naked eye.
Color uniformity is equally solid at a low error of 1.74 Delta E. That’s nowhere near visible and represents one of the better results we’ve measured overall.