Hi Walker and Keith.
Thanks for looking into this.
Just a quick recap. When I started to do the first linearisation, the test target for some reason printed (with the master curve), very dark.
My exposure time was to long but even after adjustment the test target was really dark.
I tried to linearise but the the program overcorrected to a very light print, and in the next step a very dark print and so on and on.
Walker, you thought that the reason for this was my light source and you sent me a set of curves made for a doped mercury lamp, to use as a starting point for my own linearisation.
( I use a light source with UV-tubes and a vacuum frame, bought from the Palladio company ).
So I printed a negative with the curve mentioned above and in the parts of the negative supposed to be just clear film there is density.
This is not a curve generated by me, I don’t know if you call it a master curve but it is one that you sent me.
When I print a test target from this negative and make a linearisation, I get a nicely corrected curve and the following test target looks good except that I don’t get maximum blacks.
I don’t mean max black as in the areas not covered by film, but max black where the paper has been covered just by the Pictorico film.
Of course I get the same result when printing the first test target, but the problem doesn’t change for better or worse after my first linearisation.
Would it be possible for you to change the curve so it doesn’t lay down any density where the negative should be clear ?
I should also add that when I make a negative with one of the master curves I get none of this problem, the darkest parts of the image are completely clear.
For information, I print with the Malde-Ware process and also with the traditional palladium-ferric oxalate process.
I enclose a screen shot from the measurement of a test target so you can see that there are no reversals or false values.
This may sound like a small problem but the change in dMax is clearly visible to the eye, and in my mind a Platinum-Palladium print with higher dMax always looks better than one with lower dMax.