Grayscale, Gamma & Color
Our grayscale and gamma tests are described in detail here.
The BM320 essentially offers two grayscale choices: the factory-calibrated modes, and the user mode, which can be adjusted. Differences between the two are small.
The first two charts show the Adobe RGB and sRGB modes. Rec.709 is identical to sRGB in this test. You can see that there are slight blue errors that just touch the 3dE threshold at 90 and 100%. We don’t consider that a problem. Our only complaint is that we can’t calibrate these modes any further. For that, you must engage the User mode, which restricts you in terms of color space. We’ll show you how that works in the color tests below.
We went ahead and adjusted the RGB sliders and achieved decent grayscale tracking that averaged 1.33dE.
Since the User mode doesn’t offer a standard gamut choice, we’re only including the grayscale results from our Adobe RGB and sRGB measurements. In both the pre- and post-calibration test, the BM320 finishes mid-pack. While this is acceptable for professional applications, we would rather see the numbers posted by the top three screens from Dell, BenQ, and NEC. It’s a small detail that can’t be seen with the naked eye, but we’re particular about these things.
Like grayscale, gamma cannot be adjusted in the factory-calibrated modes. But Acer has included a nice bit here. You’ll notice that the third chart shows an average value closer to 2.4 for the Rec.709 mode. That standard, used in most television production as well as Blu-ray disc and streamed content, employs the BT.1886 gamma which is fairly close to the 2.4 power function. We compared the BM320’s measurement to both references and found it tracked closer to the latter. In the User mode, the gamma also tracks closer to 2.4, even when the preset is on 2.2.
None of the screens here have any significant gamma issues, so the BM320’s fifth-place finish is not a concern. Tracking is tight and stays close to 2.2 in the Adobe RGB and sRGB modes. Rec.709 offers similar accuracy at a 2.4 level. There is nothing to complain about, especially when looking at the color results, which are quite good. We’ll show you those now.
Color Gamut & Luminance
For details on our color gamut testing and volume calculations, please click here.
There are a lot of charts here so bear with us. Clearly, Adobe RGB, sRGB, and Rec.709 are pretty much right on target. Thanks to good grayscale and gamma tracking, saturation and luminance results are both excellent with low average error levels. The slightly-blue white point pulls the magenta secondary a little off-hue, but it isn’t too far from perfect. Remember that Rec.709 uses a 2.4 gamma. That has been considered in our tests, which show excellent saturation tracking.
The last two charts show the BM320’s native gamut. You can see that blue and green is fine, but red is quite over-saturated. We tried fixing it with the 6-axis saturate sliders but only succeeded in reducing luminance, not saturation. If you want the slightly better grayscale tracking offered in User, you’ll have a lot of bonus red in the image. This might be of use for some, but if you need accuracy, stick with the factory-calibrated presets.
Once again, the Dell, BenQ, and NEC take top honors thanks to their excellent calibration controls. The BM320 runs with the rest with low errors in both Adobe RGB and sRGB modes. The Rec.709 average error was a similar 1.92dE. We consider this adequate for professional applications, but some users may wish to employ a software calibration solution like CalMAN or X-Rite for ultimate accuracy.
Gamut volume is slightly below 100% in both the Adobe RGB and sRGB spaces. Again, that fits in with the competition. Only the Dell UP2715K gets within a hair of 100% for both. The BM320 offers slightly more volume than the bottom three screens.
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