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.
We measured every color temp mode to find the best out-of-box result. While the sRGB option claims to be 6500 K, our results showed a Delta E error of 6.49, which is quite high. The best preset to use is number two, which measures an average of 4.46 Delta E. The chart above shows the Native preset, which is the default setting. With a steep decline in blue as you get brighter, whites look quite warm in this mode.
Here’s the chart after calibrating the number two preset.
This is an excellent result, especially in the 50- to 80-percent brightness range. The rise in blue at 90 and 100 percent isn’t too bad; in fact, it shouldn't be visible. You’ll need to back off the Contrast control to tame the brightest whites.
Let’s bring our comparison group back into the mix.
We used the result from color temp mode two in the final comparison. It’s still visibly warm, but better than NEC's Native preset. A 4.46 Delta E is the best we could do. It’s disappointing that the sRGB preset doesn’t measure below a Delta E value of 3, especially for a monitor this expensive. Remember that you can’t adjust the sRGB preset. Memories 1, 2, 3, and 5 are fully adjustable.
Fortunately, after calibration, the results are much better.
A 1.14 Delta E measurement puts the EA294WMi in second place here, and sixth overall for 2013. We would like to see better stock numbers at NEC's $750 price point, but those who choose to calibrate will be rewarded for their efforts.
Gamma is the measurement of luminance levels at every step in the brightness range from 0 to 100 percent. This is 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 gamma charts below, the yellow line represents 2.2, which is the most widely accepted standard for television, film, and computer graphics production. The closer the white measurement trace comes to 2.2, the better.
We're quite pleased with the EA294WMi's result. We’ve seen gamma results that range from fair to poor in many monitors, but NEC does well in this metric. Flat gamma tracking at 2.2 means that image depth and dimensionality will be consistent, no matter what content you're looking at. Obviously, NEC’s choice to omit gamma control is not a problem.
Here’s our test group again for the gamma comparisons.
Just like the trace in the picture above, you can see that the EA294WMi exhibits very flat gamma tracking performance. Though we’d love to see multi-point gamma controls on every monitor, it wouldn’t make much difference here.
We calculate gamma deviation by simply expressing the difference from 2.2 as a percentage.
Our best screens deviate from the correct gamma by only a few percent at most. NEC's EA294WMi is comfortably in that group. The 3.18-percent deviation we measured represents a maximum error of less than 7 cd/m2.