Grayscale Tracking And Gamma Response
Our grayscale and gamma tests are described in detail here.
Straight out of the box, the U2879VF generates a decent grayscale tracking chart. You can see a little green creeping in as brightness levels rise but the error never gets too far past 4dE. Though the tint is visible, it has only a minor impact on image fidelity.
Calibrating the color temperature brings all errors below 2dE except for the 10 percent level, which is still under the visible threshold. We'd be perfectly satisfied with this result from any gaming or general-use monitor but there is more potential to be discovered.
The best performance of all comes from the sRGB preset, which is in the color temp menu rather than the picture mode options. It's a different approach than we've seen on other monitors. This is our preferred preset, though we lament the lack of a brightness control. You'll have to accept a max output level of 228cd/m2 if you go this route.
Here is our comparison group.
With no adjustment you'll see an average grayscale error of 3.15dE. Simply selecting the sRGB preset takes that down to an excellent .93dE. No wonder AOC saw fit to include a calibration data sheet. While many pro-displays generate slightly better numbers the U2879VF comes awfully close for a lot less money.
Our adjustments result in a respectable average error of 1.53dE. This is more than adequate for any gaming application. If you can deal with a fixed white level, the sRGB mode is clearly the best choice with almost non-existent errors.
The default gamma setting is preset 1, which is just a tiny bit dark. If the U2879VF had higher contrast this would be OK but in this case, it makes the image a tad dull. Our calibration includes a change to the gamma option.
After adjusting the RGB sliders and changing the preset to Gamma 2 we have a chart that tracks 2.2 a little more closely and adds some punch to the image.
The sRGB gamma is fixed slightly below 2.2 (lighter). We think this is ideal for this particular monitor's contrast profile. Again, the output level cannot be changed but it's still the best possible image you can get from this panel.
Here is our comparison group again.
We compared the U2879VF's sRGB mode to the other screens here. Tracking is very consistent with only a .07 variation between the highest and lowest values.
We calculate gamma deviation by simply expressing the difference from 2.2 as a percentage.
With tracking that rides below the 2.2 line, we recorded a five-percent deviation from the standard. The actual average value is 2.09. It's not ideal from a measurement standpoint but we think this particular gamma behavior is appropriate here.