Grayscale Tracking And Gamma Response
Our grayscale and gamma tests are described in detail here.
The VP2780-4K ships in its Native mode, which cannot be calibrated. There is an adjustable User mode, but for reasons we’ll explain, it’s not the best choice.
In the default Native mode, there are no visible grayscale errors. Delta E values start to climb a little in the 90 and 100 percent levels, but only a meter can see anything wrong. It matches the results on ViewSonic’s factory calibration sheet included with the monitor.
In User mode, extreme accuracy is possible with very precise RGB sliders. As you can see, the resulting chart is almost perfect. Unfortunately that’s the only good thing about the User mode. Gamma controls are locked out in favor of a less-than-ideal curve that affects color saturations negatively. For work requiring critical color accuracy, User mode is not the right choice.
The best way to use the VP2780-4K is in its sRGB mode. All errors are under two Delta E, with many under one. You’ll also get the best gamma and color gamut accuracy.
1.48dE represents the Native mode. It’s perfectly usable and beats every other screen in the group except for the amazing EA244UHD.
1.37dE is not the lowest error possible from the VP2780-4K (we achieved .81dE in User mode) but it represents the only other accurate preset: sRGB. It still ranks well with the other professional displays here. The only way to do better is with a software solution like CalMAN that generates a software lookup table.
Here is the reason why the User mode doesn’t work for us. The gamma tracking shown here is far too light, especially as brightness levels rise. The net effect is inaccurate color saturation in mid-tones, which we’ll show you on the next page. Since the gamma presets are inexplicably locked out in User mode, there's nothing that can be done about this issue.
Fortunately, the gamma tracking is pretty good in both Native and sRGB modes. There is a small dip at the 10-percent level, and an even smaller hump at 80 percent. Neither anomaly causes any issues with color saturation. While it’s not the best gamma tracking we’ve seen, it compares reasonably well with the other screens compared here.
The slight aberrations at 10 and 80 percent spoil this result. Though it finishes last among these elite displays, a .38 variance is still quite good compared to the broader group of monitors we’ve tested.
We calculate gamma deviation by simply expressing the difference from 2.2 as a percentage.
The gamma deviation result is much better because the average values stay close to 2.2. While this bodes well for perceived contrast, it’s also important to the color saturation results — read on to see what we mean.