QTR-Quadtone RIP

Roy,

thank you so much for that clear and informative explanation.


Keith

--- In QuadtoneRIP@yahoogroups.com, Roy Harrington <roy@h...> wrote:
>
> Hi Keith,
> 
> There are two basic philosophies with Soft-Proofing and ICC 
printing.
> 
> The first is where you print without using any color management 
> conversions.
> The soft-proof here is to show you on the screen how the image will 
> look on the print.
> The assumption is that the driver has some builtin tonal 
> characteristics and you are
> just simulating them during soft-proofing.   To set up soft-
proofing 
> for this you select
> "Preserve Color Numbers" -- this means the numbers in the file go 
> directly to the driver.
> The Assign Profile you did doesn't change the numbers in the file 
so 
> for printing it's
> effectively no change.  You "see" a change on the screen because 
the 
> file-to-screen
> always has color management in effect -- the new profile gives the 
> numbers a new meaning
> so they get converted differently for display.  If you were 
printing 
> directly from Photoshop
> it would be like selecting "Same as Source" or "No Color 
Management".
> -- your case basically illustrates this mode, the print comes out 
> lighter and the
>     softproof could be used to show this.
> 
> The second philosophy is the more complete mode.  Here the idea is 
to 
> use the
> ICC profile for two functions.  First the profile is used for 
printing 
> so that the color
> management can match and convert the input file profile to the 
driver 
> profile and make
> the print look as close as possible.  Then the same ICC profile can 
be 
> used for soft-proofing
> to show what differences still exist.  For grayscale the main 
> difference will be the hue of
> the print.  To setup this soft-proofing the "Preserve Color 
Numbers" is 
> turned off -- its
> assumed that you will print using this same profile.  PW and IB try 
to 
> account for the
> differences between screen b/w and print b/w.   To print using a 
> profile you must
> Convert-to-Profile rather than Assign-Profile.  This will convert 
the 
> file numbers into the
> print profile space.  If you were printing directly from PS this 
would 
> be the same as selecting a
> print profile  in the Print-with-Preview page.
> 
> The QTR-Create-ICC could be used in either way but usually in the 
> second way.
> But the 2.3.0 version is a gray-only ICC so the soft-proofing won't 
> show any difference
> but it is effective as a printing profile.  Version 2.3.1 has color 
> soft-proofing so should
> give the full second method.  There is a problem right now with the 
> white-point of this.
> 
> Roy
> 
> On Saturday, October 15, 2005, at 10:34  PM, fitness2health wrote:
> 
> > I am having some problems soft-proofing.
> >
> > My setup is Windows XP, Photoshop CS and an Epson 1270.  I have
> > created a curve using QTR v 2.3.10 for Kirkland Photo Paper with 
UT-
> > FSN  (but using the 3 gray inks only – i.e. not using PK). I am 
using
> > QTR Gray Lab as my workspace with perpetual intent. I set up an 
ICC
> > profile using the QTR-Create-ICC (both from v 2.3.10 and v 2.3 – I
> > could not see any difference.).
> >
> > The problem I am having is getting the monitor to match the 
output. I
> > load an image and change the image mode to grayscale (I.e. Gray 
Lab)
> > from RGB.
> > ·	If I then "Assign Profile" using the ICC I made with QTR-
> > Create-ICC (in my case QTR-UTFSN-KirkPP-AllGrays), I see a 
lightening
> > of the screen image which is then similar to the print.
> > ·	However, if I set up a Proof Setup Custom using the ICC (QTR-
> > UTFSN-KirkPP-AllGrays), which I do without any image loaded in
> > Photoshop, and check BPC, but not PW or IB, I do not see any 
change
> > in the image. BUT, if I check Preserve Color Numbers (which hides 
the
> > BPC checkbox) I see the same lightening of the screen image
> > as "Assign Profile".
> >
> > My question therefore is when using soft proof profile should I 
use
> > BPC or Preserve Color Numbers, because it looks like the latter is
> > being used by "Assign Profile"?
> >
> > Any help is hugely appreciated
> >
> > Keith Prue
> >
> > PS. Aside from this I am having great output with QTR.
> >
> >
> >
> >
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
> -
> Roy Harrington
> roy@h...
> Black & White Photo Gallery
> http://www.harrington.com
>