QTR-Quadtone RIP

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@...
Black & White Photo Gallery
http://www.harrington.com