2015-02-08 by richard@...
Like I said earlier in the thread, I have been kept awake with this problem off and on for the last few months/years and it all started clicking earlier last week. partly due to the conversation about the problems with QTRs linear "curve" and the reason for needing ICC profiles to match the print space to the working space. I still think using the ICC profile with QTR severely blocks up the shadows, so I was attempting to map the .quad values to a "modified gamma" curve and print without color management—kinda going in-between where there is an increased smooth transition to the dark shadows but not the hard dip that results in using the ICC profiles. The natural next step is to be able to map any existing .quad profile to different targets—either a straight linear line or "modified gamma". There is some problem if the original profile is "too far off" but what I have been testing is a way to get away from the QTR linearize function, and only use QTR to build the raw profile using the ink limits and gray overlaps. I just did a three print test series with K6 inks and that approach worked better than the standard QTR profile creation workflow of linearizing a raw curve with the 21 step target and then creating an ICC profile (or printing with just the straight line increase).
All this came about because I figured out that my 1430 I use for testing at home is so far out of whack that no profiles other people have created work for this printer. I am looking into getting it replaced but since I need to build profiles from scratch, i developed some tools and methods for making it easier. I then take what I am doing to the studio and test on a properly functioning 3800 with Cone inks, and a 9900 with Epson inks.
Anyway. I am still testing and refining all this so I don't want to get too far ahead of myself here, but I am working on something that could be very interesting, and could solve a lot of problems linearizing wonky printers, or just make the standard QTR workflow less prone to error. I am not sure how it would translate to digital negatives yet, but that might just be the next step.
Richard Boutwell