Monitor calibration

[Flavio Rose]

I've been thinking of buying a monitor calibrator and am a little confused on two points:

a) What does monitor calibration do?

b) Are there PC laptops that can't be calibrated?

I am thinking only of LCD screens, not CRTs or other types.

Re point a), I am guessing based on books that calibration creates a file called a "profile" which says what each of the 3x256 pure colors on the monitor are in terms of some absolute standard of color and intensity (Lab, Luv, or whatever). However, I have also read that instead of relying on software to apply the profile each time something is drawn to the screen, calibrators attempt to write values into registers in the graphics adapter so that software sees a graphics device with standardized color response, i.e., where each possible RGB value sent to the graphics adapter results in a standardized color and intensity on the screen (possibly with the intensity scaled to take into account the brightest intensity that the screen is capable of creating or that the user has chosen).

Re point b), if the calibration software writes values into graphics adapter registers, the laptop has to actually have those registers in its graphics adapter. In addition, the laptop's operating system, drivers, and firmware have to respect the values written and not reset them back to a standard value at random (and indeed may have to rewrite the values set by the calibrator into the adapter each time the laptop boots). In addition, the screen's native response to RGB values has to be stable enough that calibration doesn't have to be repeated frequently. Do all modern PC laptops meet these conditions?

Any advice on this would be most appreciated.

[Axel Hildebrandt]

Calibrating the monitor creates an ICC profile, which the computer will use instead of the standard profile. You can calibrate laptops, too. The results depend of course partially on the quality of the screen.

[Steven Read]

You might try support@gretagmacbeth.com I am using the eye-one display 2. It mentions on the box that it is for all types of monitors, including LCD,CRT and laptops. Am quite happy with the product. Steve