QTR-Quadtone RIP

Dear Roy,
I have followed carefully your instructions in the "Making a B&W ICC
with a Scanner" writeup.
Here is my workflow:

1) Open in PS CS2 the 21-step.tiff file. Reply "do not assign any
profile" to the request of colour management

2) Print with preview on EEM with Epon R2400 using:
      a) Let printer determine colors
      b) intent perceptual
In the printer property dialog:
      c) ABW with default settings

3) Scan the print with a HP Scanjet 4870 adjusted in order to get the
0%, 50% and 100% patch according to your writeup.

here are the mesurements done with PS:
Gray   Lab_L
0%     96
5%     96
10%    94
15%    88
20%    83
25%    77
30%    71
35%    65
40%    59
45%    53
50%    47
55%    43
60%    39
65%    36
70%    31
75%    27
80%    23
85%    20
90%    17
95%    16
100%   16
Kodak Gray Card   42

4) I used the above measurements to create curve  QTRgui and ICC
profiles in QTR_Create_profile.exe.

5) In both cases, the profiles produced provided very poor results
(softproofs and prints dont quite match).

I have done many tests using both QTRgui adn PS with the profiles I
created. I wasted time and material with no  success.

I came to the conclusion that the scanner is not properly calibrated.
Infact, adjusting the canner settings to match only 3 patches (as you
suggest) may be insufficient, unless the scanner is very linear (wich
is not, just by looking at the abve table of measurements.

Would you be so kind, please, to give more measurements of other
patches of the 21.step.tiff file so I could calibrate my scanner
a little better?

Thank you very much 
Sincerely
  Daniela

Roy did not write the tutorial "Making a B&W ICC with a Scanner". It was written by Paul 
Roark:

http://home1.gte.net/res09aij/Making_B-W_ICCs.htm

I'm not sure this will help but I noticed the Gray values have "%" sign and Paul recomends 
this format: 95.00 not "95% ". So I don't know if the ICC profile is written properly with the 
"%" sign. Here Roy could answer if % sign will confuse the ICC building script.

> I wasted time and material with no  success.

Welcome to the club! You are not wasting time and material...you are learning how this all 
works.

Best,

John



--- In QuadtoneRIP@yahoogroups.com, "dgattarino" <dgattarino@...> wrote:

>
> Dear Roy,
> I have followed carefully your instructions in the "Making a B&W ICC
> with a Scanner" writeup.
> Here is my workflow:
> 
> 1) Open in PS CS2 the 21-step.tiff file. Reply "do not assign any
> profile" to the request of colour management
> 
> 2) Print with preview on EEM with Epon R2400 using:
>       a) Let printer determine colors
>       b) intent perceptual
> In the printer property dialog:
>       c) ABW with default settings
> 
> 3) Scan the print with a HP Scanjet 4870 adjusted in order to get the
> 0%, 50% and 100% patch according to your writeup.
> 
> here are the mesurements done with PS:
> Gray   Lab_L
> 0%     96
> 5%     96
> 10%    94
> 15%    88
> 20%    83
> 25%    77
> 30%    71
> 35%    65
> 40%    59
> 45%    53
> 50%    47
> 55%    43
> 60%    39
> 65%    36
> 70%    31
> 75%    27
> 80%    23
> 85%    20
> 90%    17
> 95%    16
> 100%   16
> Kodak Gray Card   42
> 
> 4) I used the above measurements to create curve  QTRgui and ICC
> profiles in QTR_Create_profile.exe.
> 
> 5) In both cases, the profiles produced provided very poor results
> (softproofs and prints dont quite match).
> 
> I have done many tests using both QTRgui adn PS with the profiles I
> created. I wasted time and material with no  success.
> 
> I came to the conclusion that the scanner is not properly calibrated.
> Infact, adjusting the canner settings to match only 3 patches (as you
> suggest) may be insufficient, unless the scanner is very linear (wich
> is not, just by looking at the abve table of measurements.
> 
> Would you be so kind, please, to give more measurements of other
> patches of the 21.step.tiff file so I could calibrate my scanner
> a little better?
> 
> Thank you very much 
> Sincerely
>   Daniela
>

My apologies to Paul.
John, I dont have the % sign in the file I feed to QTR_create_ICC nor
to the linearization process of QTR Create Curves.
I still think the problem is with the scanner calibration.
Anybody will be so kind to check my workflow and/or give the
Lab_L values measured for the 12-step wedge printed with the R2400
and ABW?
Thanks in advance.
   Daniela

--- In QuadtoneRIP@yahoogroups.com, "John Vitollo" <jvlist@...> wrote:
>
> Roy did not write the tutorial "Making a B&W ICC with a Scanner". It
was written by Paul 
> Roark:
> 
> http://home1.gte.net/res09aij/Making_B-W_ICCs.htm
> 
> I'm not sure this will help but I noticed the Gray values have "%"
sign and Paul recomends 
> this format: 95.00 not "95% ". So I don't know if the ICC profile is
written properly with the 
> "%" sign. Here Roy could answer if % sign will confuse the ICC
building script.
> 
> > I wasted time and material with no  success.
> 
> Welcome to the club! You are not wasting time and material...you are
learning how this all 

> works.
> 
> Best,
> 
> John
> 
> 
> 
> --- In QuadtoneRIP@yahoogroups.com, "dgattarino" <dgattarino@> wrote:
> >
> > Dear Roy,
> > I have followed carefully your instructions in the "Making a B&W ICC
> > with a Scanner" writeup.
> > Here is my workflow:
> > 
> > 1) Open in PS CS2 the 21-step.tiff file. Reply "do not assign any
> > profile" to the request of colour management
> > 
> > 2) Print with preview on EEM with Epon R2400 using:
> >       a) Let printer determine colors
> >       b) intent perceptual
> > In the printer property dialog:
> >       c) ABW with default settings
> > 
> > 3) Scan the print with a HP Scanjet 4870 adjusted in order to get the
> > 0%, 50% and 100% patch according to your writeup.
> > 
> > here are the mesurements done with PS:
> > Gray   Lab_L
> > 0%     96
> > 5%     96
> > 10%    94
> > 15%    88
> > 20%    83
> > 25%    77
> > 30%    71
> > 35%    65
> > 40%    59
> > 45%    53
> > 50%    47
> > 55%    43
> > 60%    39
> > 65%    36
> > 70%    31
> > 75%    27
> > 80%    23
> > 85%    20
> > 90%    17
> > 95%    16
> > 100%   16
> > Kodak Gray Card   42
> > 
> > 4) I used the above measurements to create curve  QTRgui and ICC
> > profiles in QTR_Create_profile.exe.
> > 
> > 5) In both cases, the profiles produced provided very poor results
> > (softproofs and prints dont quite match).
> > 
> > I have done many tests using both QTRgui adn PS with the profiles I
> > created. I wasted time and material with no  success.
> > 
> > I came to the conclusion that the scanner is not properly calibrated.
> > Infact, adjusting the canner settings to match only 3 patches (as you
> > suggest) may be insufficient, unless the scanner is very linear (wich
> > is not, just by looking at the abve table of measurements.
> > 
> > Would you be so kind, please, to give more measurements of other
> > patches of the 21.step.tiff file so I could calibrate my scanner
> > a little better?
> > 
> > Thank you very much 
> > Sincerely
> >   Daniela
> >
>

"dgattarino" wrote:

> 2) Print with preview on EEM with Epon R2400 using:
>       a) Let printer determine colors
>       b) intent perceptual


Above should be: "No Color Management"

This setting is for printing out the grayscale. 

After the grayscale ramp is scanned and an .ICC profile is made then print with "Let 
Photoshop Determine Colors" should be used with the new QTR .ICC profile.

That's the title of a short paper by Paul Roark in January 2006.  He
seemed fairly satisfied with the quality of the QTR profiles that he
was making with an Epson Expression 1600 flat-bed scanner (in lieu of
a densitometer or spectrophotometer).

I'm considering going the same way... but with an Epson 1680, which
can still be acquired new (unlike the 1600).  What do you folks think?
 Is this likely to be satisfactory?  Are any of you happy using
scanners... or are you convinced that a densitometer is the only way
to go?