Results: Grayscale Tracking
All of the IPS panels we’ve tested recently display excellent grayscale tracking, even at stock settings. It’s important that the color of white be consistently neutral at all light levels from darkest to brightest. Grayscale performance impacts color accuracy with regard to the secondary colors; cyan, magenta, and yellow. Since computer monitors typically have no color or tint adjustment, accurate grayscale is key.
To perform a manual calibration of the VP2770-LED, we employed the User color mode. The other modes lock out the RGB adjustments. Selecting the sRGB preset also prevents use of the Contrast and Brightness sliders. The pre-calibration chart below reflects the User mode with the RGB controls set to their default positions.
The color of white tends a bit towards blue as the signal level rises. The error becomes visible at 40 percent, and hits a max of just over six Delta E at 100 percent. This is a slightly cool tone and an average out-of-box result.
After calibrating the VP2770-LED, the grayscale tracking is quite excellent. Only small adjustments need to be made to bring everything in line.
Our final settings are Red 98, Green 100, and Blue 94, with contrast set to 70 and Brightness to 42. This is perfect tracking with an average Delta E error of only 0.8604. It doesn’t really get much better than this.
As mentioned earlier, the S27B970D offers several unique options with its color modes. The first chart is the factory-calibrated mode. As previously stated, the only way to adjust this is to use the Natural Color Expert software with a supported color probe. The chart below represents the monitor in its default state.
The result is somewhat green in hue, with the error increasing as the light level goes up. The error becomes visible at 50 percent and it hits a max Delta E of just under six. Given a choice, we’d rather see blue errors than green because the human eye is most sensitive to green, and therefore better able to detect that error.
This is the Standard mode measurement. The green error is still present, but slightly lower. Visibility doesn’t occur until 80 percent, and the max Delta E is now under four.
If you don’t plan to calibrate the S27B970D, we recommend Standard mode. The color is pretty accurate without adjustment, and you’ll be able to control brightness and contrast.
After a manual calibration, the results are just a hair short of perfect.
Calibrating the Standard mode produces one of the best charts we’ve ever seen. Only zero and 10 percent are over one Delta E, and that can even be attributed to instrument error. While the human eye cannot distinguish between the Samsung and ViewSonic monitors we're measuring, we remain very impressed by this level of accuracy.
All of the monitors we’ve tested recently show an extremely low grayscale error right out of the box. While we recommend calibration of any panel, you can still enjoy an accurate image from any of these screens at their stock settings.
The Samsung S27B970D is the only panel to measure under three (average Delta E). This result is for the monitor’s Standard mode; the factory-calibrated mode measured higher, with an average Delta E of 3.76.
After calibration, both the Samsung and ViewSonic panels had essentially no grayscale error. This is near-perfect performance.
In most cases, calibration will yield a reasonable improvement over the stock image. With the monitors reviewed here, the improvement is more significant. It should be noted that Samsung’s Natural Color Expert software was not able to achieve a grayscale error this low. The best we could do was 2.14 Delta E average. The obvious conclusion is that a manual calibration is preferable for the S27B970D.