Results: Viewing Angles And Uniformity
Screen Uniformity: Luminance
To measure screen uniformity, zero- and 100-percent full-field patterns are used, and nine points are sampled. In a change from previous reviews, we’re now comparing the results to other monitors we’ve measured. First, we establish a baseline measurement at the center of each screen. Then the surrounding eight points are measured and their values 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.
As we mentioned earlier, the Uniformity Compensation feature is effective but not entirely without compromise. Remember the ANSI contrast test, where turning it on reduced the result by 25 percent. Here is the upside of that. In a black field pattern, we see a 1.65-percent improvement. We can’t see them but our C6 luminance meter tells us the hot spots are in the upper-left, upper-right, and lower-right corners.
The following chart reflects the white field measurement.
The improvement is even more significant in this test, to the point that Dell's UP3214Q takes the crown as the monitor with the best white field uniformity ever seen in our labs. Even with the compensation off, it comes in at a very respectable 9.06 percent. Interestingly, the other screen with an extremely low result, Samsung’s S27B971D, also has a uniformity compensation feature.
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.
The uniformity look-up table scores another victory in the color test. While a Delta E variation of 4.53 isn’t too bad, 1.31 is even better. If you leave the compensation off, there's an obvious flaw in the lower-right corner where we can see a slight green tint. Removing that measurement from the equation results in a 2.73 value. It’s likely that another sample would measure differently.
