Black And White Uniformity, Viewing Angles
Another measurable aspect of panel performance is brightness uniformity. Most manufacturers calibrate displays based on the center point of the screen. However, every area of the screen behaves differently. Sometimes you can get better performance in one specific region. As a result, we added a nine-point black and white luminance test to measure the performance of each monitor's panel.
| Dell UltraSharp U2711 | ||
|---|---|---|
| White Luminance cd/m^2 | ||
| 181.2630 | 180.5343 | 142.577 |
| 195.8545 | 200.0100 | 160.9077 |
| 200.0313 | 202.1060 | 172.9605 |
| Black Luminance cd/m^2 | ||
| 0.2737 | 0.1950 | 0.2309 |
| 0.3024 | 0.2726 | 0.1787 |
| 0.3727 | 0.2580 | 0.2184 |
The U2711 appears to have slightly poor white luminance in the upper right-hand corner and poor black luminance in the bottom left-hand corner.
| DoubleSight DS-277W | ||
|---|---|---|
| White Luminance cd/m^2 | ||
| 187.7542 | 177.9022 | 162.4172 |
| 194.8163 | 199.1000 | 166.1605 |
| 200.4431 | 202.9104 | 165.4207 |
| Black Luminance cd/m^2 | ||
| 0.7940 | 0.8487 | 0.7247 |
| 0.7960 | 0.7812 | 0.7308 |
| 0.9060 | 0.8992 | 0.8512 |
Black luminance is fairly even, though this doesn't alleviate the poor contrast issues cited earlier. The DS-277W demonstrate less uniformity with respect to white luminance, as there's a noticeable deficit on the right-hand side. Color production isn't affected when you view the display at wider angles, but the lack of white uniformity makes the right side seem slightly less vibrant than the left side.
| NEC PA271W | ||
|---|---|---|
| White Luminance cd/m^2 | ||
| 186.8910 | 190.8966 | 173.7275 |
| 193.0134 | 201.6654 | 185.0052 |
| 186.3268 | 196.0234 | 184.4747 |
| Black Luminance cd/m^2 | ||
| 0.1997 | 0.1710 | 0.4115 |
| 0.1814 | 0.2006 | 0.1669 |
| 0.3519 | 0.2761 | 0.1792 |
We are able to calibrate the center of the screen to 200 cd/m2, but this offsets other regions, as white uniformity radiates outward from the center. Black luminance seems to behave differently. In the upper right- and bottom-left corners, the PA271W struggles to produce deep blacks. But this is only apparent if you're viewing the monitor at extreme angles.
