wiredfool

In which I get a reference calibration.

To figure out what was really going on, I calibrated the display with a $$$ GretagMacbeth EyeOne that’s used in the local print shop and compared the results.
First, a problem image, screen captured from my camera. Note that this image has blue and yellow/green fringes in the mid gray regions. This is an all gray image, so there should be no color there. (The absolute colors are off here due to the capture).
That same image, using the monitor calibration from the EyeOne, shows a smooth grayscale and no color banding.

The OS profile for this monitor shows a little color banding, but nowhere near as much as the Huey profile, and not enough to show on one of these screenshots.

After seeing the EyeOne calibration, it’s not the monitor, it’s the calibration. Comparing the calibrations, it’s pretty clear that they significantly differ, at least in the curves.

First, the gamut plots. In order, there’s the OS profile, the Huey, and the EyeOne:
The as shipped configuration is clearly out in left field, it’s punchy and saturated, but no good for accuracy. The other two are closer together — enough so that I’d believe that it’s attributable to sensor and measurement accuracy as much as anything else. They both have very similar white and green points, but the red and blue are farther out on the EyeOne.

Os:

Huey:

EyeOne:

And the individual RGB Channel Curves:

Huey:

EyeOne:

The color space is roughly consistent between the two calibrated profiles, but the individual channels were calibrated in the EyeOne Software, but only the neutral r+g+b was calibrated wit the Huey. As one might expect, the EyeOne made the gray images look gray.

So now what? The Huey works well on other lcds, I’m guessing that the display circuitry in the laptop is just more nonlinear between the channels than most video cards, and the Huey (as much as any color matching system can be) is for the common systems. It should be possible to fix this with a more extensive calibrating regime, one where each channel is sampled individually. Spending $1000 on a calibration system realy does get you more than $80. And if you have a MacBook, the Huey is not what you want for calibrating the internal monitor.

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