QTR-Quadtone RIP

Roy

I am printing with NO Color Management.  After I build the profile, and linearize it....I am 
finding that the highlights and shadows are no longer as nicely separated as the pre 
linearized print.   Linearizing appears to compress the tones to the middle.  Highlights are 
lighter, shadows are deeper.  What I expect linearization to do is the opposite.  I expect an 
evenness to each tone change when I print the step wedge.

On another printer, I was able to successfully make a fine set of profiles...beginners luck I 
suppose.   I am puzzled why I am having this trouble now.  

My procedure is as folllows.  1.  Partition inks  2.  Print 21 step wedge tests and tweak the 
profile without any linearization until I get a well separated smooth print.  In QTR, I am 
printing each test with the prelinearized profile selected.  3.  Print a 21 step to 
measure....measure...and paste in the values....then reinstall.  4.  The graphed linearized 
curve upon installation looks kosher (no errors)...so I make one more print using  the now 
linearized profile.  21 steps are compressed on either end when using the linearized 
profile...not as nice as the pre linearized print.  I would expect the opposite...better 
separation post linearization.

I am not making ICC profiles...is this essential?  I am simply printing from QTR and 
selecting the appropriate pre or post linearized profile.

Out of frustration last evening, I went back to IJC/OPM and made a new profile that is 
perfect in less than 10 minutes.   The reason I really want to learn QTR is that more 
printers are supported.  But I am having a heck of a time getting the results I expect.

I trust I am simply doing something wrong here, but for the life of me...I cannot find it.  
Thanks for any advice you can provide.

Phil







> Are you printing using an ICC print profile?  i.e. in Photoshop Print page
> or with No Color Management.   If you use NoCM then it will depend
> on what file profile you use.
> 
> Roy
> 
> On 8/9/08, brouwerkent <philip@...> wrote:
> > Howdy
> >
> > I have linearized what I believe is a well done profile, but when I print with the 
linearized
> > profile...the print is  darker than anticipated.  I am able to make a good print by 
moving the
> > Gamma setting in the print settings to a lower setting ( lighter).  Of course I would like 
to
> > have a more optimum profile not requiring this last stage adjustment.
> >
> > Any ideas how to readjust my profile to be closer to correct output?  Please 
understand the
> > linearity is fine...very smooth with no bumps or posterization.   Output is just too 
dark....
> >
> > I am thinking that perhaps I have set the basic ink limit too high.  Any other ideas of 
how I
> > might correct my profile?
> >
> > Thanks
> >
> > Phil Brouwer
> >
> >
> >
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
>