QTR-Quadtone RIP

I wrote up a pdf QTR tutorial that hopefully makes things clear for both simpler uses (canned curves) and more advanced setups. The tutorial is based on an UC K3 setup on a 3800, but the concepts apply to other quad configurations.
The link is on my blog at 
<blogfiftygreatestphotos.com/2009/07/21/quadtone-rip-workflow>

Thanks, Amadou, for this excellent write up on QTR workflow.  I've
added links to
both the PDF and the blog on the QTR website.  This is a Mac oriented
description
but I'd recommend it for both Mac and Windows users who want more understanding
of QTR workings from beginner to advanced features.

Thanks again,
Roy

On Tue, Jul 21, 2009 at 8:34 AM, Amadou Diallo<amadiallo@...> wrote:
> I wrote up a pdf QTR tutorial that hopefully makes things clear for both simpler uses (canned curves) and more advanced setups. The tutorial is based on an UC K3 setup on a 3800, but the concepts apply to other quad configurations.
> The link is on my blog at
> <blogfiftygreatestphotos.com/2009/07/21/quadtone-rip-workflow>
>
>

Super. Thank you, Roy.

On Tue, Jul 21, 2009 at 1:34 PM, Roy Harrington <roy@...> wrote:

>
>
> Thanks, Amadou, for this excellent write up on QTR workflow. I've
> added links to
> both the PDF and the blog on the QTR website. This is a Mac oriented
> description
> but I'd recommend it for both Mac and Windows users who want more
> understanding
> of QTR workings from beginner to advanced features.
>
> Thanks again,
> Roy
>
>
> On Tue, Jul 21, 2009 at 8:34 AM, Amadou Diallo<amadiallo@...<amadiallo%40gmail.com>>
> wrote:
> > I wrote up a pdf QTR tutorial that hopefully makes things clear for both
> simpler uses (canned curves) and more advanced setups. The tutorial is based
> on an UC K3 setup on a 3800, but the concepts apply to other quad
> configurations.
> > The link is on my blog at
> > <blogfiftygreatestphotos.com/2009/07/21/quadtone-rip-workflow>
> >
> >
>
>  
>



-- 
amadou diallo
www.blogfiftygreatestphotos.com


[Non-text portions of this message have been removed]

Amadou/Roy,

I note in Amadou's Level 1 workflow that you convert to grayscale Gray Gamma 2.2. In the past I had downloaded gray-lab.icc and rgb-lab.icc profiles along with some paper specific .icc profiles. After I scan a negative I convert to gray-lab.icc. When I use the Photoshop print function I choose Gray-Matte-Paper.icc as my generic working profile. I understand that once I get to the point of creating paper/ink specific icc profiles that I can then use them here but for the time being they're working well with my workflow with paper-specific QTR curves. So, my question is is it preferable or desirable to use Gray Gamma 2.2 over the gray-lab.icc profile? Also, I no longer seem to be able to find the various gray and rgb-lab profiles via the website. Am I missing them somewhere else? Thank you both: Roy for a great piece of software and Amadou for helping me make sense of it.

Carl Socolow


--- In QuadtoneRIP@yahoogroups.com, amadou diallo <amadiallo@...> wrote:

>
> Super. Thank you, Roy.
> 
> On Tue, Jul 21, 2009 at 1:34 PM, Roy Harrington <roy@...> wrote:
> 
> >
> >
> > Thanks, Amadou, for this excellent write up on QTR workflow. I've
> > added links to
> > both the PDF and the blog on the QTR website. This is a Mac oriented
> > description
> > but I'd recommend it for both Mac and Windows users who want more
> > understanding
> > of QTR workings from beginner to advanced features.
> >
> > Thanks again,
> > Roy
> >
> >
> > On Tue, Jul 21, 2009 at 8:34 AM, Amadou Diallo<amadiallo@...<amadiallo%40gmail.com>>
> > wrote:
> > > I wrote up a pdf QTR tutorial that hopefully makes things clear for both
> > simpler uses (canned curves) and more advanced setups. The tutorial is based
> > on an UC K3 setup on a 3800, but the concepts apply to other quad
> > configurations.
> > > The link is on my blog at
> > > <blogfiftygreatestphotos.com/2009/07/21/quadtone-rip-workflow>
> > >
> > >
> >
> >  
> >
> 
> 
> 
> -- 
> amadou diallo
> www.blogfiftygreatestphotos.com
> 
> 
> [Non-text portions of this message have been removed]
>

I also am struggling with the same issue  of what to do with GG 2.2 or Graylab ...  And how to use it. 

When I started out I was advised scan in untagged gray, only assign profiles, and edit in 16bit.  Never convert. This way you do as little damage as possible to the original numbers when circumstances dictate a change in profile.  The caveat was this would mean more work & time as you would have to readjust curves each time you change the profile. Have I got this right?

I am trying to understand what is happening with each setting. I am a bit confused when I look at Carl's question. Carl says:
> When I use the Photoshop print function I choose Gray-Matte-Paper.icc as my generic working profile.<

What confuses me is I thought the working profile is assigned in the color preferences settings Ps-cs3, and it is a default profile which Ps uses if you do not assign or convert to a profile. And Gray Matte is not intended as a working profile?? Is it an option Here??

In the Ps Print dialogue box you assign a Printer Profile, and I have been sitting here all morning trying to visualize what is happening when I set the Printer Profile. Is it just adjusting ink flow or is it a calibration curve. Or is it adjusting the flow in each of the nozzles?? 

Right now I have found that I get pretty good prints with either Gama 2.2 or QTR_Graylab checked here  .. If I go to the recommend QTR_Gray_Matte or QTR_Gray_photo I am getting too much ink with photo and even more with Matt. On a Hanamuhle Photorag.

I thought the profile for the printer was assigned in the curve in the QTR print page??

Anyway  ... I know this is a little more then Carl's question ... but I too am trying to figure out which profile to use and how to use it. Any help is appreciated.

michael
Using mac pro/ os10.5.7 / cs3 / epson 7600 / Cone k7 / Assign Gamma 2.2 / Printer Profile QTR Gray Lab/ Curve HanPhotorag







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

>
> Amadou/Roy,
> 
> I note in Amadou's Level 1 workflow that you convert to grayscale Gray Gamma 2.2. In the past I had downloaded gray-lab.icc and rgb-lab.icc profiles along with some paper specific .icc profiles. After I scan a negative I convert to gray-lab.icc. When I use the Photoshop print function I choose Gray-Matte-Paper.icc as my generic working profile. I understand that once I get to the point of creating paper/ink specific icc profiles that I can then use them here but for the time being they're working well with my workflow with paper-specific QTR curves. So, my question is is it preferable or desirable to use Gray Gamma 2.2 over the gray-lab.icc profile? Also, I no longer seem to be able to find the various gray and rgb-lab profiles via the website. Am I missing them somewhere else? Thank you both: Roy for a great piece of software and Amadou for helping me make sense of it.
> 
> Carl Socolow
> 
> 
> --- In QuadtoneRIP@yahoogroups.com, amadou diallo <amadiallo@> wrote:
> >
> > Super. Thank you, Roy.
> > 
> > On Tue, Jul 21, 2009 at 1:34 PM, Roy Harrington <roy@> wrote:
> > 
> > >
> > >
> > > Thanks, Amadou, for this excellent write up on QTR workflow. I've
> > > added links to
> > > both the PDF and the blog on the QTR website. This is a Mac oriented
> > > description
> > > but I'd recommend it for both Mac and Windows users who want more
> > > understanding
> > > of QTR workings from beginner to advanced features.
> > >
> > > Thanks again,
> > > Roy
> > >
> > >
> > > On Tue, Jul 21, 2009 at 8:34 AM, Amadou Diallo<amadiallo@<amadiallo%40gmail.com>>
> > > wrote:
> > > > I wrote up a pdf QTR tutorial that hopefully makes things clear for both
> > > simpler uses (canned curves) and more advanced setups. The tutorial is based
> > > on an UC K3 setup on a 3800, but the concepts apply to other quad
> > > configurations.
> > > > The link is on my blog at
> > > > <blogfiftygreatestphotos.com/2009/07/21/quadtone-rip-workflow>
> > > >
> > > >
> > >
> > >  
> > >
> > 
> > 
> > 
> > -- 
> > amadou diallo
> > www.blogfiftygreatestphotos.com
> > 
> > 
> > [Non-text portions of this message have been removed]
> >
>

Carl and Michael,

The whole ICC profile situation can be confusing.  There are so many
ways to do things that just about
every recommendation you see will be different.  There is no "best"
way per se, the main thing I think is
to get into a workflow that YOU can do consistently so you come to
understand what to expect.
None of this makes better quality prints -- it's all about making it
easier to edit files on the screen
and judging what the print will look like.

You don't really have to understand what profiles are all about but I
think it helps (at least some people)
to get a feel of what's going on underneath.  Fortunately we're
talking about B&W and just one dimension.
Three dimensional color cubes are much harder to visualize.  So, what
is a profile?  It's simply a mapping
of the numbers in the file with Luminosity.   Since they all go from
whitest (dMin) to darkest (dMax) the
only real issue is the shape of the curve from min to max.  To
experiment:  take a stepwedge and Assign
a couple different profiles to it.  Notice the numbers stay the same
but the Luminosity varies with the
different profiles.

There are two major functions you might do with profiles and it's
worthwhile understanding the difference
and what they do.  First, Assign Profile simply attaches a profile to
a data file.  None of the values in the
file are changed -- this just assigns "meaning" to those numbers.  If
you are looking at the file on the
screen its likely that the appearance may change.  If there was a
previous profile it is thrown away.
Second, Convert-to-Profile invokes color management.  It takes all the
values in the file and changes
them so that the "meaning" i.e. Luminosity is preserved.  It uses the
old profile to get the Luminosity
and changes the value to get the same Luminosity with the new profile.
 Whenever you apply a
print profile you are doing a Convert-to the print profile.

For grayscale work the profiles that you are likely to run across are
Gray Gamma 2.2, Gray Gamma 1.8,
and Gray Lab.  The gamma curves have been around for a long time and
use a simple exponential
curve for the mapping.  GG 2.2 is a steeper curve and darker than GG
1.8.  Luminosity however is
not evenly spaced.  I created the Gray Lab profile that has a
different curve with the benefit that the
Luminosity is evenly spaced.   In the current times using 16-bit files
all of them have way more
gray values than you will need so its not critical which you use.

In 16-bit conversions are not very bad but in general "less is
better".  Most of my work has been
scanned B&W negatives so without any apriori profile I've mainly
Assigned Gray Lab and done all
my editing there in 16-bit.  If you do digital capture and switch from
color to B&W it may be
useful to use the same gamma in RGB and grayscale.  AdobeRGB has a
Gamma 2.2 curve so
they are a good pair to use.  ProPhoto has a Gamma 1.8 curve so that
is another pair.
You should be setting these up in Photoshop Color Settings.

One more consideration is that on Windows the QTR print workflow is
often used without a
print profile.  So the Cone K7s curves have been setup for using Gamma
2.2 -- that is their
standard workflow.

I'll address some specific questions below:

On Wed, Jul 22, 2009 at 9:36 AM, csandersoc<csocolow@mindspring.com> wrote:
> Amadou/Roy,
>
> I note in Amadou's Level 1 workflow that you convert to grayscale Gray Gamma 2.2. In the past I had downloaded gray-lab.icc and rgb-lab.icc profiles along with some paper specific .icc profiles. After I scan a negative I convert to gray-lab.icc.
----  usually you'd be Assigning GrayLab or Gamma 2.2 not converting.

When I use the Photoshop print function I choose Gray-Matte-Paper.icc
as my generic working profile.
--- Gray Matte Paper and Gray Photo Paper are generic print profiles.
 Working spaces in Photoshop
--- should be either Gamma or Gray Lab.

I understand that once I get to the point of creating paper/ink
specific icc profiles that I can then use them here but for the time
being they're working well with my workflow with paper-specific QTR
curves. So, my question is is it preferable or desirable to use Gray
Gamma 2.2 over the gray-lab.icc profile? Also, I no longer seem to be
able to find the various gray and rgb-lab profiles via the website.
--- On the Mac there are in:  /Library/Printers/QTR/icc

Am I missing them somewhere else? Thank you both: Roy for a great
piece of software and Amadou for helping me make sense of it.
>
> Carl Socolow
>

On Wed, Jul 22, 2009 at 1:17 PM, mberman89<j6mb@...> wrote:
> I also am struggling with the same issue  of what to do with GG 2.2 or Graylab ...  And how to use it.
>
> When I started out I was advised scan in untagged gray, only assign profiles, and edit in 16bit.  Never convert. This way you do as little damage as possible to the original numbers when circumstances dictate a change in profile.  The caveat was this would mean more work & time as you would have to readjust curves each time you change the profile. Have I got this right?

I'm not sure I understand what you mean.  Once you assign a profile
(GG2.2 or GrayLab) you edit but never change
the profile again in the master file.  There is no readjusting ever.

>
> I am trying to understand what is happening with each setting. I am a bit confused when I look at Carl's question. Carl says:
>> When I use the Photoshop print function I choose Gray-Matte-Paper.icc as my generic working profile.<

Only choose Gray Matte Paper as a print profile.

>
> What confuses me is I thought the working profile is assigned in the color preferences settings Ps-cs3, and it is a default profile which Ps uses if you do not assign or convert to a profile. And Gray Matte is not intended as a working profile?? Is it an option Here??
>
> In the Ps Print dialogue box you assign a Printer Profile, and I have been sitting here all morning trying to visualize what is happening when I set the Printer Profile. Is it just adjusting ink flow or is it a calibration curve. Or is it adjusting the flow in each of the nozzles??

All the print profile does is Convert-To-Profile the data on the fly
as it's send to the driver.  The Print Profile characterizes
the print driver so this matches the Luminosity in the file with the
Luminosity on the print.  The whole and only
purpose is to match the print with what you edited on the screen.
It's never an absolute perfect conversion but
the best given reflective paper versus bright screen.  You still need
to "learn" how to judge what you'll get
out of the printer.

Roy

>
> Right now I have found that I get pretty good prints with either Gama 2.2 or QTR_Graylab checked here  .. If I go to the recommend QTR_Gray_Matte or QTR_Gray_photo I am getting too much ink with photo and even more with Matt. On a Hanamuhle Photorag.
>
> I thought the profile for the printer was assigned in the curve in the QTR print page??
>
> Anyway  ... I know this is a little more then Carl's question ... but I too am trying to figure out which profile to use and how to use it. Any help is appreciated.
>
> michael
> Using mac pro/ os10.5.7 / cs3 / epson 7600 / Cone k7 / Assign Gamma 2.2 / Printer Profile QTR Gray Lab/ Curve HanPhotorag
>

Carl,GG 2.2 has a couple of advantages. For non-color managed bw workflows
like Epson's ABW, a file encoded with GG 2.2 onscreen will come closer to
the printed densities because that is the tone curve the driver is assuming.
Of course, in a fully color-managed workflow the embedded profile won't
matter. But for bw it seems GG 2.2 has become the standard, so it's good to
get in the habit of using it. Like Roy has stated, the main thing is to use
a consistent approach.

On Wed, Jul 22, 2009 at 12:36 PM, csandersoc <csocolow@...>wrote:

>
>
> Amadou/Roy,
>
> I note in Amadou's Level 1 workflow that you convert to grayscale Gray
> Gamma 2.2. In the past I had downloaded gray-lab.icc and rgb-lab.icc
> profiles along with some paper specific .icc profiles. After I scan a
> negative I convert to gray-lab.icc. When I use the Photoshop print function
> I choose Gray-Matte-Paper.icc as my generic working profile. I understand
> that once I get to the point of creating paper/ink specific icc profiles
> that I can then use them here but for the time being they're working well
> with my workflow with paper-specific QTR curves. So, my question is is it
> preferable or desirable to use Gray Gamma 2.2 over the gray-lab.icc profile?
> Also, I no longer seem to be able to find the various gray and rgb-lab
> profiles via the website. Am I missing them somewhere else? Thank you both:
> Roy for a great piece of software and Amadou for helping me make sense of
> it.
>
> Carl Socolow
>



-- 
amadou diallo
www.blogfiftygreatestphotos.com


[Non-text portions of this message have been removed]

amadou diallo <amadiallo@...> wrote:
>
> ...for bw it seems GG 2.2 has become the standard, so it's good to
> get in the habit of using it. ...

I've used Gray Gamma 2.2 for some time now in a Windows environment.  My workflow involves saving a "printing only" file to the desktop that has been re-sized to whatever I want and also has a curve applied to it to adjust for the differences between the linear QTR space and the non-linear GG 2.2 space.  

See http://www.paulroark.com/BW-Info/Eb1400.pdf at page 10 for a graph that illustrates the different spaces' characteristic curves.  The Photoshop *.acv curve I use for the adjustment is in the following Zip file: 
http://www.paulroark.com/BW-Info/Eb-1400-Profiles.zip 

The PDF at http://www.paulroark.com/BW-Info/Eb1400.pdf includes my basic (Windows) QTR ICC and RIP workflows.  I used the 1400 and this modified Eboni-6 (with HP PK black only option) at the Golden Trout Photo Workshop this year.

Paul
www.PaulRoark.com