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Results: Grayscale Tracking And Gamma Response

NEC EA274WMi Monitor Review: Eco-Friendly At 2560x1440
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A 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 had to explore a few different options to find the best out-of-box color temp and best starting point for calibration. Since the Standard picture mode is the most neutral, we stuck with that and measured all of the presets. You might think that sRGB would be a good set-and-forget option, but you'd be wrong in this case.

The grayscale tracking in sRGB mode is only fair. Errors become visible at the 40-percent level and rise from there to almost eight Delta E at 90 and 100 percent. The chart shows red and green tracking upward, while blue drops off at the highest brightness levels. The overall tint looks green to the naked eye. For a monitor at this price point, the sRGB preset should be closer to an average error of three Delta E. And there are no RGB sliders available in that mode, either.

Switching to the Color Temp 3 preset is a step in the right direction.

If you lack tools to calibrate the EA274WMi, this mode works pretty well without further adjustment. Red and blue only fall off gradually as brightness rises, while green tracks slightly upward. The green tint is still visible above the 50-percent level, but only barely.

Working the RGB sliders brings us to a much higher standard of accuracy.

Our final measurement run is just what we’re looking for from an $800 monitor. All errors are now well under two Delta E. We did have a little challenge getting the 90- and 100-percent levels under control. Reducing the Contrast to 43 did the trick there. If you’re willing to accept slight green errors at the highest brightness levels, leaving it at 50 improves the on/off contrast to around 1000 to 1.

As shipped, the EA274WMi comes set to its Standard picture mode and Native color temp preset. We suggest changing to Color Temp 3, at least. Then you should match our pre-calibration results.

For a pro-level display, this is below-average performance. Many of the screens we test now fall below the three Delta E threshold without calibration. Our result of 4.20 Delta E represents the Color Temp 3 preset. Native is slightly higher at 4.38, and sRGB is the highest at 4.77.

The obvious conclusion is that the EA274WMi benefits greatly from calibration.

A 1.01 Delta E error is pretty close to the best displays we’ve tested. As you’ll see later in the color gamut tests, calibration improves accuracy across the board.

Gamma Response

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 gamma 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.

We’re only showing you one gamma result because it’s what you’ll see no matter what color temp setting you choose. There are no gamma controls on the EA274WMi, so we’re glad the results are so consistent. Aside from miniscule dips at 10 and 70 percent, this is a perfect chart. The maximum measured luminance error is 3.7 cd/m2.

Here is our comparison group again.

A .12 variation represents extremely flat gamma tracking. That kind of consistency is important no matter what the image source. Only three other screens of our last 22 have scored higher in this test. The tracking runs from a low of 2.09 to a high of 2.21.

We calculate gamma deviation by simply expressing the difference from 2.2 as a percentage.

You can expect the same tight gamma tracking from the EA274WMi in every color temp preset using the Standard picture mode. As we said, preset three provides the best grayscale tracking, but if you want to use a different white balance setting, gamma does not change.

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