Digital BW, The Print

I need to take a closer look.  I agree that from both a hypothetical and
practical (depending on how bad the linearity is) perspective a more linear
set of LUTs makes ICC profiling easier and more effective.  I also need to
look more closely at the inbuilt menu-driven colour calibration feature of
the 4800.  I glanced over this the other day while trying to figure out the
roll paper features.  I've not gone back to it.

But again we are drifting a long way from B&W if you adopt the premise that
a colour ICC profile managed workflow doesn't yet work well for B&W.  I do
think this conversation is better had on another list lest we bore everyone.
;-)


> From: Ernst Dinkla <E.Dinkla@...>
> Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Date: Tue, 04 Oct 2005 11:41:14 +0200
> To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Subject: Re: [Digital BW] more colorbase misc.
> 
> 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