We performed all grayscale, gamma and color tests in the VG259QM’s Racing mode. The mode’s reasonably accurate out of the box, but calibration (see our recommended settings on page one) took it to a very high level.
Grayscale and Gamma Tracking
We describe our grayscale and gamma tests in detail here.
The VG259QM’s default white point is a bit cool at brightness levels above 50%, making the picture look brighter but at the expense of image depth. Setting grayscale to the correct 6500K color temp made things look more three-dimensional.
Gamma is also a tad light with values averaging 2.11. While this helps make shadow detail more visible, it desaturates color a little.
After calibration, the VG259QM exhibited near-perfect grayscale tracking. This is pro-level performance. Unfortunately, gamma was a little lighter from our adjustments, though the panel’s solid contrast helped mitigate that. We’d like to see gamma presets added to the OSD so we could get closer to 2.2.
The VG259QM’s average grayscale error of 3.41 Delta E (dE) is OK out of the box, but you should really calibrate for the best image. In this comparison, the VA screens have a slight edge in accuracy and, along with the HP’s TN panel, make our Calibration Not Required list.
After our calibration, the VG259QM rocketed to the top of the comparison group in the grayscale error test with a tiny average error of just 0.24dE. That’s one of the lowest scores we’ve ever recorded, and very impressive for any monitor, especially a gaming display. Our changes made a visible improvement to image quality.
Gamma runs with a tight range of values, which helps keep contrast solid but the calibrated average of 2.06 (6.36% deviation) is lighter than it should be. The image doesn’t suffer too much but a higher gamma would improve color saturation and depth for all content.
Color Gamut Accuracy
For details on our color gamut testing and volume calculations, click here.
With the light gamma tracking, we expected the VG259QM to show under-saturation in all colors, but only red seems affected. Red’s not too far off the mark though. Green, meanwhile, is right on target ,and blue is actually slightly over. The principal issues are the hue errors in cyan and magenta, which you can fix with grayscale adjustments.
We’ve managed to improve the average error to 2.25dE with no visible errors present. Red is a little more vibrant, and blue is better balanced. And the secondaries are now much closer to their targets. This is solid performance.
Though the VG259QM’s 2.59dE color score is a good one, it is up against stiff competition here. We would enjoy the image on any of these monitors. Once you get below 3dE, errors are extremely hard to spot.
Though the VG259QM is an sRGB monitor, it delivers a little bonus blue; hence the extra 10.2% of color volume. If you want to use it for color-critical work, a software profile is necessary. At 74.33% coverage, this is in no way a DCI-P3 monitor but it is a little more colorful than the Samsung, HP and Acer displays -- at least in its reproduction of blue. It’s a small difference in practice, but the Asus’ sky and water effects will be a tad more brilliant.
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