Digital BW, The Print

Steve Kale wrote:
> Yes but from what I can see Colorbase does not linearise the printer.

Steve,

The targets I see in the Colorbase 4800 setup show 264 
patches, all density ramps. It still could be that they are
measured against non linear tables and the ends to fixed Dmax 
numbers but at first sight they look very much like
linearisations targets. The targets and the tables are 
arranged per paper/resolution setting file, the numbers 
probably chosen in a way that they are fitting the paper specs 
best. 33 is a lot of gradation patches I have to admit.
What makes you think that Colorbase is not linearising the 
printer ?  Different step rates doesn't say much, the only
thing that could indicate a different approach is setting the 
patch densities against the internal tables and see a non 
linearity.

The way to control it is sending a common CcMmYKkk 
linearisation target after calibration through Colorbase with 
the same paper/resolution settings. The calibration has to be 
active then and that is the hard hack. Using Photoshop and the 
printerdriver with CM off and no printer profile will still 
have the CMYK>RGB>CcMmYKkk conversion in the process.

And even when it is not a strict linearisation it wouldn't 
make much difference for custom profile creation as that has 
worked before as well. Any odd method of giving consistency 
would work. It could even be a perceptual curve and profiling 
wouldn't suffer :-)

                    --
           Ernst Dinkla


www.pigment-print.com
(         unvollendet         )