Grayscale Tracking And Gamma Response
Our grayscale and gamma tests are described in detail here.
During the OSD tour we mentioned the metamerism option, which is turned on by default. Here is its effect on grayscale tracking in the Adobe RGB mode. It isn’t a huge difference from standard, and the error isn’t really visible. But it’s not quite as accurate as a monitor of this caliber should be, and it doesn’t match the results found on the factory calibration data sheet. However, the bit of extra warmth here should help reduce eye fatigue during long work sessions.
We’re showing a post-calibration result, but no white balance adjustments were necessary to achieve the above chart. Metamerism is now off, along with a change to gamma and one color value. This is perfect for all intents and purposes.
The sRGB mode shows a similar result, and again, we made no changes to the white balance controls. This is what we expect from a premium display.
Here is our comparison group.
The above chart shows out-of-box results for all screens. Our PA302W sample is ready for work without any need for adjustment. There’s no reason to calibrate it other than to satisfy ego.
So of course we did calibrate and managed to lower the average error levels by measureable and completely invisible amounts. This is excellent performance; just what we’re accustomed to from NEC’s PA-series monitors.
Metamerism seems to have a tiny effect on gamma tracking. The values ride just under 2.2 with a small dip at 90 percent. It’s subtle, but in a professional product there’s room for improvement.
After turning metamerism off and changing the gamma preset to 2.3, we recorded a much better result. This works for both Adobe RGB and sRGB modes. We can still see a minor dip at 90 percent, but it’s nothing to be concerned with.
Here is our comparison group again.
A .19 range of values is very low, but among our professional screens, it isn’t a top result. This issue alone is far from a deal breaker however. It’s just extreme nit-picking on our part.
We calculate gamma deviation by simply expressing the difference from 2.2 as a percentage.
The PA302W misses an average value by only .01 with a 2.19 result. It represents an invisible error and is far from being a problem.