Pascal, Please take a look at Eizo ColorNavigator v5+ on www.eizo.com. Eizo makes good monitors. Have a look at their PDF documentation if you're interested. It explains that they have incorporated in their latest software versions a set of unique correction coefficients for a variety of supported instruments. Roger > As far as I know, a colorimeter, doesn't know anything about matrix > coefficients, it > just measured colors... And the software calculates the matrix > coefficients... > > Regards, > Pascal de Bruijn