17" LCD Part V: Four Panels Compared

The Principle

The LaCie spectrometer takes the form of a palette that is placed over the glass of the monitor. After starting the application, you are invited to adjust the screen brightness and contrast manually, using the following chart.

The calibration provides a DeltaE graphics setting for monitors. The setting corresponds to the difference measured between the color requested and the one actually reproduced. A DeltaE of less than or equal to 1 is the equivalent of perfect calibration. There should be no perceptible difference between the original color and the color reproduced. Problems only arise when DeltaE = 3 or more. This time, the human eye can distinguish between two shades. As far as it is concerned, LaCie considers the calibration as having been successful as soon as DeltaE is less than or equal to 2.

In the coordinates, the values range from black (0) through white (100).

In the case of the reference graphic provided above, this means that:

• DeltaE < 3 = 97% of the colors displayed, from dark gray through white, are true.
• Delta E < 2 = 95% of the colors displayed are of high enough quality to be considered as very true.
• DeltaE < 1 = 92% of the colors are perfectly reproduced on the screen.
• Delta E > 3 = 3% of the colors displayed are not true. The darkest (including black) are simply impossible to reproduce (area without a curve).

Response Time Statistics - Just Write Any Old Stuff (I)

The response times suppliers associate with their panels vary, anywhere from 16 ms to 25 ms. The only problem is that these figures mean nothing. Or at least, not a lot. An article published in 2001 that can be viewed at Xtremtech explains the situation pretty well, and we have summarized it for you in the section entitled "RT between colors". But this isn't the only problem...