Gamma, Calibration, and Viewing Angles


When we first fired up the NX-VUE24, the first thing to strike us was that the display just didn't seem to have as much contrast as we expected even from a TN panel. The display appeared washed out, even at the default 'Gamma Off' setting, which Nixeus claimed was tuned to what should be a very high contrast value of 2.6. Displays are typically tuned for a Gamma value of 2.2, and Nixeus told us that the 'Gamma On' setting shoots for that value. We tried it and did some quick visual tests:

Now that just seemed way off. The gamma chart showed a value *way* lower than 2.2, and the viewing angle test couldn't even be performed properly. The 'lagom' text is supposed to blend into the grey background at 'good' viewing angles, yet this display was vividly showing those words when viewed directly ahead.

We continued to tinker, viewing from different angles, and found that the viewing angle required for the display output to line up with what we expected required a very odd viewing angle:

As you can see from the trapezoidal shape of the screen border, we had to position the camera at table level to achieve these results. This is most certainly not the way a user is going to view a display, but we did note that we could view the display from a 'normal' viewing angle with the gamma setting returned to the default 'Off' (2.6) position. It seems the higher gamma was an intentional choice by Nixeus to compensate for the pixel angle of this particular panel.

To confirm what we were seeing, I ran some quick checks using HCFR:

Gamma Off (2.6):

Gamma On (2.2):

As you can see, the 'straight ahead' viewing angle of the colorimeter shows some ugly results here. While the Gamma Off setting was supposed to give better color, its measured gamma still comes in at only 1.9. The Gamma On setting which is claimed to shoot for the standard 2.2 actually comes in at 1.6. Typical TN panels don't hit 1.6 unless you are looking at them from an extreme angle.

To describe what is going on here, think about what happens when viewing a typical TN panel. As you move your head above or to the sides, the panel contrast drops and colors are washed out. You could increase the display Gamma to try and compensate for this, but then the image would not look correct when viewed straight on. Now, what if the 'straight on' angle was no longer perpindicular to the glass and was at an angle that you would never practically view the panel from? Getting a consistent / good calibration would be tricky at best since all angles are now resulting in a lower ocntrast state, but since you are looking at the display 'off axis' from most angles (straight ahead also being off axis in this case), viewing angle performance should actially *increase*. The trick is getting good colors out of a display that is fighting to be washed out.

To try and solve this problem, I first ran a calibraion using the 'Gamma On' (2.2) setting as Nixeus recommends in their review guide and product manual. Results were reasonable for a TN panel, and viewing angles were surprisingly good (based on what was described above), but when we fired up a game, colors became noticably washed out. This was because color profiles only apply to the Windows desktop and are not applied by game engines.

To solve this problem, we went against the Nixeus recommendation and calibrated the display with the 'Gamma Off' (2.6) setting chosen. We were still able to achieve a reasonable calibration even at this 'extreme' gamma setting. This is a trickier calibration, as we have the firmware pushing gamma in one direction while the display itself fights in the other direction, which makes the calibraion of darker greys far more difficult for a typical calibration profile. It should be noted that in both cases, the calibration profiles were making only small changes to color values. The more major changes were being done to correct the gamma response of this display. Also, the gamma correction with 'Gamma On' (2.2):

…was far more significant than what was required when calibrating with 'Gamma Off' (2.6):

We therefore recommend calibrating this particular display set at 'Gamma Off ' (2.6). The added bonus is that gamma will remain at reasonable levels while gaming. Here was the end result of this calibration:

As you can see, the 'lagom' text requires a proper gamma value for that test to be successful, and with the display calibrated, it works out quite well, even when viewed from the side.

Calibration Profile Download

The Windows color profile management interface is a bit of a mess, with the need to select and enable a profile in multiple layers of the interface. The best guide for loading and enabling a profile can be found over at TFTCentral. We used the following tools to generate our own calibration profile:

Our calibration profile was created using the lowest calibration speed in a dimly lit room. Here are the required settings if you wish to use our profile:

  • "Gamma Off" (2.6) ("Gamma On" not recommended by PCPer)
  • Brightness: 40
  • Contrast: 50
  • Preset: User Define
  • Red: 70
  • Green: 63
  • Blue: 62
  • Profile download: (HERE)

The above profile was created specifically for a color temperature target of 6500K at a luminance of 120 cd/m2 (nit). Gamma 2.2. Remember that the only way to get a correct calibration on your specific panel is by using a colorimeter on that very panel. The above settings and profile will only get *your* display to a perfect calibration if it has the exact same properties as our test sample. A perfect match is unlikely, but this should get you far closer to calibrated than just running with defaults, especially with the odd gamma issues we saw with this particular display.

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