Colormunki: find the max black
2008-07-05 by Marco Brambilla
Hi all, As a first step to calibrate a new paper we need to find the blackest black the printer is capable of. I think a colorimeter should be more precise than the human eye, so I am trying with the colormunki. However, numbers per se mean nothing, also, measuring twice the same sample gives slightly different results, an any engineer would expect. What is a significant difference ? for example, pls see this table: Printer: Epson R1800, UC Inks, Ink#1 (which I hope is the MK) Paper: Harman MATT FB Mp Dark Grayish Brown 1 45 20.63798 1.31831 2.700665 Dark Grayish Brown 2 50 19.86762 1.149479 2.581927 Dark Grayish Brown 3 55 19.45193 1.079633 2.199622 Dark Grayish Brown 4 60 19.00063 1.036125 2.080517 Black 5 65 18.80058 0.933541 1.84603 Black 6 70 18.62351 0.913706 1.684894 Black 7 75 18.91697 0.857361 1.656826 Black 8 80 18.78215 0.76134 1.581838 Black 9 85 18.99918 0.73042 1.576031 Black 10 90 19.14227 0.730163 1.361232 What we see is that at 75% there is an inversion, which to me means that the paper becomes saturated or however no longer linear. Remember, here we're in Calibration Mode. So I would think that 70% is the limit for this paper. However, from 70% to 65% the difference in L is 0.008 (0.2 in density). Is this truly visible to the human eye, even after linearization ? Thank you for your thoughts Ciao, Marco. [Non-text portions of this message have been removed]