Grayscale, Gamma & Color
Our grayscale and gamma tests are described in detail here.
Some Asus gaming monitors work well in their default Racing picture mode, but our VG245H sample looks a little too blue. This cold tint reduces image depth a bit. You could switch to a warmer color temp preset or perhaps engage the Blue Light Filter. The greater issue here is gamma tracking, which we’ll get to in a moment.
The best fire-and-forget mode is sRGB. That offers a slightly warm white balance, but the errors are barely above the visible point. It also sports improved gamma and color gamut accuracy. The only drawback is that you’re stuck with 195cd/m2 max output. Since that’s our ideal level, it works for us, but your experience may vary depending on room lighting conditions.
Since FPS games are the main reason for buying a FreeSync monitor, we measured that preset as well. Its whites are extremely blue by default. You can calibrate it or choose a warmer color temp, but gamma and color are still off in this mode.
Returning to the Racing mode and performing a grayscale calibration results in superb performance. Combined with a drop in the contrast control, the VG245H is now almost perfectly dialed in.
Out of the box, Racing mode returns a 7.24dE average grayscale error. Selecting sRGB drops that figure to 2.89dE which is pretty good. If you plug in our recommended settings, you’ll get close to the .85dE number we recorded after making our adjustments. That’s pro-level performance, and the VG245H looks really good when properly set up.
As you can see, gamma is another area that needs attention. It’s not just to straighten out the tracking but also to improve color saturation at all image levels and tighten up color balance. Racing runs a bit light, and the too-high contrast setting creates a clipping situation between 90 and 100% brightness. sRGB tracks a little better, but contrast is still at the clipping stage though it’s less noticeable. The FPS picture mode is completely washed out from a gamma that’s very light and clips detail significantly. The fix is to adjust the RGB sliders and lower contrast from 80 to 69. That brings every brightness level into view and fixes our color balance issues.
Calibration results in a perfect 2.2 gamma average value which puts the VG245H on top of the group. The trace shows slight variations at 10 and 80%, but they are not of consequence. The range of values is reasonably tight at .31 from bottom to top. Again that’s caused by two brightness points only. The rest are within a whisker of 2.2. This is excellent performance.
Color Gamut & Luminance
For details on our color gamut testing and volume calculations, please click here.
As we’ve mentioned in previous reviews, gamma has a huge effect on color accuracy, in both the saturation and luminance realms. In the default Racing mode, we can see how the bluish white point pulls red, magenta, and cyan off hue. The average error here is 5.38dE. Gamma is also responsible for off-target behavior of many saturation points. While the outer parts of the triangle are reasonably close, it’s the inner areas that make up the majority of actual content. Getting those right is the key to a good picture.
sRGB again proves itself to be the best mode to use without calibration. Saturation and luminance tracking are both very close to spec. The error level has now dropped to 2.53dE.
FPS is definitely a step backwards. Saturation and hue aren’t too far off but the super-high luminance levels will result in a lot of washed-out detail. The error here is 9.5dE.
Calibrating the Racing mode brings the error down to 2.22dE. While it may not seem like a big gain over the sRGB mode, it is when grayscale and gamma are taken into account. Chances are, you’ll see the best results by using our recommended settings when tweaking your VG245H.
Color error variation in our comparison group is fairly small. You'd have a tough time differentiating any of these screens if they were placed side-by-side and adjusted to equal brightness. Whether you choose the VG245H’s sRGB mode or calibrate the Racing mode, you should be happy with the image quality presented.
An initial look at the gamut triangle might suggest that the Asus would exceed the sRGB gamut volume. But even though blue is slightly over-saturated, it’s also off in hue. Notice how it leans toward the magenta secondary. If you draw a line from the blue to the green point, you’ll see that a bit of the gamut triangle is sliced off. This accounts for our 92.11% volume measurement. This isn’t a big deal for gaming or productivity. And it won’t affect video quality either. If you plan to do any proofing with the VG245H however, a custom ICC profile is recommended.