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The Q27G40XMN comes set to its Standard picture mode, which can be enjoyed without calibration if you don’t mind slightly cool tones. The native gamut is very large, making the SDR image extra colorful thanks to that Quantum Dot layer.
Grayscale and Gamma Tracking
You can see what I’m talking about in the first chart above. The Q27G40XMN runs a bit cool by default, which flattens the image a bit. The average error isn’t too bad, but pickier users will want a warmer presentation. Gamma is ruler straight and rides the 2.2 reference almost exactly.
Switching to the User color temp and tweaking the RGB sliders fixes grayscale tracking but now, gamma is skewed with too-dark values from 10-60% and a dip to too-light at 90%. While this isn’t ideal, I found after real-world observation that I preferred the calibrated image. This is a compromise for sure but ultimately for me, color accuracy won out over luminance tracking.
sRGB mode is accessed by choosing that gamut in the Color Space menu option. It can’t be calibrated, but clearly, it doesn’t need to be. It tracks grayscale and gamma with visual perfection.
Comparisons
Gamma issues aside, the Q27G40XMN definitely benefits from a grayscale calibration. The picture has more depth and texture which one would expect from the change from 3.98dE to 0.60dE. That’s a significant improvement. Gamma suffers mostly from its wide range of values which is larger than the other screens. But the average is only 2.27% off from the 2.2 reference, the actual value is 2.25, so ultimately, the compromise is worth making.
Color Gamut Accuracy
Our color gamut and volume testing use Portrait Displays’ Calman software. For details on our color gamut testing and volume calculations, click here.
The Q27G40XMN’s first gamut chart shows some interesting behavior. Large volume is to be expected from a Quantum Dot display, but AOC has tuned the hue values a bit toward BT.2020. They’re not too far from DCI-P3, so again, we’re seeing some compromise that is there to make color more vibrant. It isn’t necessarily accurate, but it is pleasing to look at. Calibration makes it better, so that’s a win. The sRGB chart is textbook perfect with every point inside the target box and a tiny 0.74dE average error.
Comparisons
The Q27G40XMN’s 3.24dE score isn’t bad, but it is enough to put it last in this group. As I said earlier, it isn’t strictly accurate, but the picture looks good. And it’s close enough that few users would complain. In the volume test, it’s only bested by the Xiaomi, which cracks 111%, one of the highest results I’ve seen from an LCD panel. The Q27G40XMN’s 104.37% is excellent, though and well ahead of the rest. It is clearly more colorful than typical wide gamut LCDs.
Test Takeaway: The Q27G40XMN isn’t strictly color accurate and requires some compromise during calibration. But the resulting picture is satisfying and colorful. It isn’t ideal for color-critical work, but it looks great for gaming, entertainment and general use.
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