Results: Grayscale Tracking And Gamma Response
The majority of monitors, especially newer models, display excellent grayscale tracking (even at stock settings). It’s important that the color of white be consistently neutral at all light levels from darkest to brightest. Grayscale performance impacts color accuracy with regard to the secondary colors: cyan, magenta, and yellow. Since computer monitors typically have no color or tint adjustment, accurate grayscale is key.
Given its color accuracy certification, the PG2401PT needs to be spot-on without user calibration. As you’ll see on the next two pages, BenQ easily earns itself a place among the most precise displays sold today.
Since most users will employ the preset sRGB and Adobe RGB modes, we measure those first.
It doesn’t get much better, with or without calibration. Nit-pickers like us will say the white point runs a tad cool, but with all errors under two Delta E, nobody will actually see a problem.
In Adobe RGB mode, the result is almost exactly the same. If you've read some of my other reviews of factory-calibrated monitors, then you know they typically don't measure this well out of the box.
To perform a calibration, we set up the two custom modes for sRGB and Adobe RGB, respectively. Our grayscale result was identical in both modes. For all intents and purposes, you are looking at perfection.
Here is our comparison group:
These are the best Delta E numbers we’ve ever recorded for an un-calibrated display. With the exception of the ViewSonic (another $1000 screen), BenQ's PG2401PT is the least-costly monitor represented.
The S27B971D remains our calibrated grayscale champion by the slimmest of margins. With errors this low, it truly is a wash though. Since the BenQ offers an Adobe RGB gamut and superior color accuracy over the Samsung, a new value leader is emerging in the professional monitor category.
Gamma is the measurement of luminance levels at every step in the brightness range from 0 to 100 percent. It's important because poor gamma can either crush detail at various points or wash it out, making the entire picture appear flat and dull. Correct gamma produces a more three-dimensional image, with a greater sense of depth and realism. Meanwhile, incorrect gamma can negatively affect image quality, even in monitors with high contrast ratios.
In the charts below, the yellow line represents 2.2, which is the most widely used standard for television, film, and computer graphics production. The closer the white measurement trace comes to 2.2, the better.
Most monitors return a few different gamma results depending on picture mode and other factors. But BenQ's PG2401PT displays the exact same flat tracking no matter which preset you choose. Again, available values range from 1.6 to 2.6 in .2 increments. Aside from the tiniest errors at 10 and 90 percent, the gamma performance is perfect.
Here is our comparison group again:
The slight aberrations at 10 and 90 percent are all that prevents the tracking from being perfect at every brightness level. The luminance errors are .19 and 1.08 cd/m2 respectively. In other words, they're barely measurable.
We calculate gamma deviation by simply expressing the difference from 2.2 as a percentage.
The average gamma value is exactly 2.2, so there is no reportable deviation. BenQ's PG2401PT chalks up another perfect result.