QTR-Quadtone RIP

Hi Fabio, I am just repeating here what we discussed off-line - for the
benefit of those following this thread (If any :)

Ok I realised what the issue is. Of course you are printing a gamma 2.2
target for the final print. So when you have linearized your printer - and
you print a target in gamma 2.2 of course you get a gamma 2.2 curve !!.  not
a linear one.

I work with L* which is a linear profile space. Because as you can see from
your curve with gamma 2.2 the shadows are very closed - I hate that.

I repeated what you had done with ABW on my 7900. When I print using QTR ICC
with gamma 2.2 target I get same result as you.
When I print with LStar  target I get a straight line - as you would expect.

LStar info is here if you want to try it out
http://homepage.mac.com/hanspeterharpf/LStar-RGB/FileSharing36.html
Google will translate the German docs :)

QTR also has an icc folder that has profiles that does the same thing for
grayscale only, but I prefer working in RGB for my b&w.

IMHO gamma 2.2 sucks.... because of the closed shadow problems. Here is a
chart of gamma 2.2 vs LStar
http://homepage.mac.com/hanspeterharpf/LStar-RGB/LStar_against_RGB.jpg

Happy printing.

Mike


On 22 July 2011 20:49, pili <fabio@...> wrote:

> **
>
>
> And here (http://i.imgur.com/fOhV0.png) is a comparison for the Canson
> Baryta Photographique 310g, before and after profiling. The 95% tones could
> be a little lighter, but the shadows are considerably better than on the
> cheaper paper.
>
> Fabio Pili
>
>
> --- In QuadtoneRIP@yahoogroups.com, "pili" <fabio@...> wrote:
> >
> > Mike,
> >
> > That cheap photo paper might be the cause of the flat curve near 95%
> tones. Look at this (http://imgur.com/vF1l5) comparison between it and
> Canson Baryta Photographique 310g, both uncalibrated. Darker tones are
> better preserved on the Canson paper.
> >
> > Fabio Pili
> >
> > --- In QuadtoneRIP@yahoogroups.com, Michael King <drmrking@> wrote:
> > >
> > > Fabio, what paper are you using?
> > > L= 93,29 is very low for paper white. Mike
> > >
> >
>
>  
>


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