Grayscale, Gamma & Color
To take the easy road with the CHG90, leave all settings at their defaults except HDMI Black Level when using an HDMI input. That should be set to Normal instead of Low. This configuration will give you nearly 90% of the DCI-P3 color gamut, which might look over-saturated to some users when viewing standard content. If you find that objectionable, select the sRGB picture mode.
Grayscale Tracking
Our grayscale and gamma tests are described in detail here.
Without calibration, the Custom and sRGB modes run slightly cool at the highest brightness steps. The error is barely visible and not worth concern. With a few adjustments to the RGB sliders, tracking is superb with all errors under 2dE and most well under 1dE. This is not the most linear chart we’ve seen but since there are no visible issues, we’re not concerned. The CHG90 offers excellent grayscale tracking performance.
Comparisons
With the 80-100% steps showing errors over 3dE, the average value before calibration is 3.13dE. That’s good enough for a third-place finish among our gaming monitor group. Since the issues are only in a small part of the brightness range, the white balance is visually perfect. Our tweaks bring the final number down to a respectable .99dE, easily professional-grade. Calibration isn’t necessary, but we think the improvement is worth the effort.
Gamma Response
The CHG90’s gamma tracking is very accurate. No matter what other changes w made, the resulting chart was the same. The above results all show Gamma Mode 1. If you’d like a brighter presentation, select Mode 2. For a darker look, go for Mode 3. In every case, the trace remained horizontal with only the slightest deviations on either side of 50% brightness.
Comparisons
The Samsung’s range of values is slightly higher than the rest thanks to those variations on either side of 50% brightness. But the final average is spot-on at 2.2, right where it should be. Since this is a VA monitor, you may prefer the darker Mode 3 setting. It offers a bit more depth but can sometimes look murky in shadow areas. You can tweak the Black Equalizer setting to bring back some of that detail. Just remember you won't be adhering to video standards.
Color Gamut & Luminance
For details on our color gamut testing and volume calculations, please click here.
By default, the CHG90’s Custom mode conforms to the DCI-P3 gamut. It came up slightly short on the cyan/green/yellow portion of the triangle, but red, magenta and blue were very close to their targets at 100% saturation. Red and blue’s inner levels were slightly under, but for the most part, we had no issues with color accuracy. Luminance levels were neutral and balanced except for the 100% points, which were a little light in red, blue and magenta.
The sRGB mode measured well in blue and green with a little over-saturation at 100% red. Again, the lower levels were closer to target. Nearly all errors were below the visible threshold for both gamuts. If you calibrate, you’ll be locked into DCI-P3 because the sRGB mode grays out all image controls except brightness. SDR games and movies will look a little more vivid than they should, but some users will likely prefer that.
Comparisons
The CHG90 starts out at a low 2.32dE average color error, which means calibration is unnecessary. Our adjustments improved that number slightly to 1.90dE. We saw a more visible gain in white point accuracy, and that’s why we prefer the calibrated image.
We’ve returned to our B group of monitors to compare DCI-P3 gamut volumes. Extended color isn’t common in gaming screens just yet, though BenQ’s EX3501 qualified for both comparison groups in this review. The CHG90 is right in the middle with just under 90% volume. Color is part of the UHD standard’s evolution, and future screens will likely be able to hit 100%. We’re just not quite there yet (even professional monitors do well to hit 95%). Since there’s plenty of bonus color, it’s easy to engage in color-critical work within the sRGB realm on the CHG90 by using a custom software profile.
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