QTR-Quadtone RIP

--- In QuadtoneRIP@yahoogroups.com, Ernst Dinkla <E.Dinkla@c...> wrote:
...
> I think that using 
> more heads + less dilutions of black  ink + effective use of droplet 
> sizes and actually using the mix you get from heads weaving (as intended 
> in the printer design) will in the end deliver less banding, better 
> linearisation, more consistency in time. I have written this before in 
> relation to BO printing and on the K7 threads.

Are you speaking of using different density K inks in parallel rather than partitioned series, 
or some combination of the two?
We discussed this once before, I thought the BO users could benefit from a the more 
complex dither that would result. I never got the chance to test it. Life is getting too short 
for all this testing.
Actually, can you assign two inks to the same part of the scale in QTR?

...
> >I'm sure this varies from RIP to RIP. I recall Roy asking if we
> >thought there would be an advantage to individual ink linearization,
> >and wonder the same thing myself.
> >  
> >
> I do not think that's wise either. Adding the separation curves after 
> linearisation introduces the imbalance of the curves themselves.  
> Profiling to the perceptual curve could smooth that out of course. It 
> will also take more time to make curves for new ink/paper combinations. 
> I have been on that route and I do not want to go back.

Believe me, with all due respect to Dan Culbertson, neither do I <G>.

...

> >I have on occassion seen an advantage to doing many more here with 4,
> >and wound up at 80. I've seen a higher count like this fix problems
> >between say 95% and 100%, more than once.
> >  
> >
> It must be quite difficult to get the readings right for 80 steps but 
> averaging readings on more targets before computing helps.

Yes, it will automatically average multiple readings of the same chart, and warn you if you 
should reread a strip due to a suspicious difference. But even with little averaging when in 
a hurry, I've only seen very occasional errors. Also, repeated linearizations are iterative, 
which helps.
But I know what you mean and was wary of potential problems at first with large patch 
counts.

> Something I did throw out in my first message: the steps in the 
> linearisation target/software are fixed on for example 5% increase. A 
> target of 30 steps with some step variation where it counts would keep 
> the target number down but increase the linearisation quality.

Seems like a great idea, I'm sure 80 for me is overkill just to get more linearization 
approaching 100%.
Tyler