Yves, what you can do is very simple: If you have a scanner, scan a simple image containing colors (a photo) a 800x600 resolution or highter. Show it on your screen and compare the colors to the original. Look and compare once in normal day light and once in (evening) electric light. You will have an idea if you need to correct or not your calibration. I have 2 computers and 2 monitors. One is a better quality then the other. This also has some importance, as both are calibrated correctly but doesn't show exactly the same gamma. :-)Guitta