QTR-Quadtone RIP

From the "Help" tab at the top of the QTR Gui page:

"You can make fine adjustments by sliding the ink limit  . . . adjustment slider. Ink limit affects the darkness of the shadows. Reducing Ink Limit can help unblock the shadows."

I found it very useful to print a 21 step wedge on a single sheet of paper using three or four different ink limit settings to see their effect. Or you could make three or four small prints on a single page of the same image with different settings.  By having them all together on a single page it's very easy to compare and see the effect of moving the slider.  

Ink density is discussed in detail on page 13 of the "User Guide" tab, also at the top of the QTR Gui page. It's too long to quote here. I'd suggest reading that and then if you have specific questions post them here. Although the QTR Gui interface has changed some since the User Guide was written, most of the things in it including ink density are still applicable I believe. 

----- Original Message ----- 
  From: David 
  To: QuadtoneRIP@yahoogroups.com 
  Sent: Monday, August 13, 2007 11:14 AM
  Subject: [QuadtoneRIP] In Curve Creation: understanding ink limit and ink density settings


  I've posted this question before, but didn't really understand the 
  answers. So again, can someone help me understand what the ink density 
  and ink limit settings do? How are they different, the same? Can 
  someone give an example of what changing these settings do? 

  I have only a layperson's understanding, so looking for help. 

  Best, David. 



   

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

I've posted this question before, but didn't really understand the 
answers. So again, can someone help me understand what the ink density 
and ink limit settings do? How are they different, the same?  Can 
someone give an example of what changing these settings do?  

I have only a layperson's understanding, so looking for help. 

Best, David.

Here is my understanding -

Whenever you are putting down ink onto paper, lighter shades require less  
ink. As you increase the amount of ink to get darker shades, you get to a  
point where more of the same ink fails to produce a darker tone. In fact,  
depending on the particular ink and paper combination, you can get to the  
point where adding more ink actually causes the tone to appear lighter.  
That is where the ink limit comes in. You want to set the ink limit so  
that the printer will never apply more ink than the level that produces  
the darkest shade possible for that ink/paper combo.

Ink density is the relative density of a particular ink to the darkest ink  
of the ink set. This setting is used by the driver software to know when  
to switch to the next lighter shade of ink instead of just reducing the  
amount of the darker ink being applied. The darkest ink is always 100 and  
the lighter inks have values less than 100. During curve creation you  
evaluate the relative densities and enter a value that represents where,  
as a percentage, the darkest level of the lighter ink lies on the curve of  
darkest ink.

This is over simplified but say if you only had two inks, the darkest  
level for the lighter ink would only get as dark and the 50% (or there  
abouts) level of the darkest ink. Then the software would start to use a  
combination of the two inks at say, 70%, and gradually reduce the amount  
of darkest ink use and increase the lighter ink use until maybe 30%, where  
it would stop using any of the darkest ink and then it would just be using  
lesser amounts of the lighter ink until you got to 0.

It gets more complicated with more inks, such as with Cone's K7 inks, but  
the principles remain the same. The whole idea is to make the transitions  
between the various ink shades as smooth as possible so that you get an  
even range of tones in the final print.

Hope this helps,
Steve

    On Mon, 13 Aug 2007 08:14:52 -0700, David <dkfreed@...> wrote:

> I've posted this question before, but didn't really understand the
> answers. So again, can someone help me understand what the ink density
> and ink limit settings do? How are they different, the same?  Can
> someone give an example of what changing these settings do?
>
> I have only a layperson's understanding, so looking for help.
>
> Best, David.
>
-- 
Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/

Hello David. I will try to help but if anyone has better words, please
chip in.
Density, as it relates to QTR, means  how dark does the ink look once
printed on the paper. It's the nature of the relationships between the
inks and papers we use to vary with different printers,inks and papers
and, to some extent, even in variations in the surrounding environment
(eg: humidity,temperatures etc). It is also true that more ink does
not necessarily mean darker. There often comes a point where the
application of more ink to the paper actually makes it look lighter
rather than darker. The use of the terms density and ink limits in QTR
are referring to this effect. We all want the maximum darkness(d'max)
as dark as possible so we try to limit the amount of ink used to be
only just enough to give us the maximum visual blackness we can get.
In practice, generally you stop somewhere just before this at a point
where increasing the amount of ink laid down stops giving significant
increases in density. You do Not want to go beyond that to where you
reverse the ever increasing darkness curve.
What I just described is in reference to the K ink but it is equally
true of the lighter inks(grays). At some point they also will max out
in their density and give no more. So when you make the calibration
prints within QTR you are, first, trying to determine what the maximum
amount of black ink you can use is(limit) and, second, once this is
determined, testing for what the darkness of each of the other
inks(grays) is at that same limit and specifically in relation to the
black ink. Those figures are then used to derive the initial control
points used for bringing the various shades in during the printing
process so you get the proper distribution of tones.
Linearizing is just a continuation of the above process by adjusting
the curves that were derived from them such that they give equal steps
across the test step tablet and replicate it properly.

All said above is a simplification, though I believe accurate, of what
the QTR RIP does and or can do. It has many controls and, beyond a few
folks who post here, most of us don't have sufficient experience and
knowledge of rips overall to be proclaiming much in the way of wisdom
in the matter. That is why it sometimes takes a while to get suitable
answers to questions. We don't really relish the possibility of being
caught out as a case of the blind leading the blind. Most will wait to
see if someone far more knowledgeable will answer first. Those people
are usually very busy and have limited time to spend in doing so.

In regards to this overall thread (Not your query), some of the
responses or complaints are a bit like a 5 year old going into a rage
because daddy won't teach him to drive the family sedan. Never mind
that he's still too small to reach the pedals and can't yet read the
road signs.

Regards
Duane
 


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

>
> I've posted this question before, but didn't really understand the 
> answers. So again, can someone help me understand what the ink density 
> and ink limit settings do? How are they different, the same?  Can 
> someone give an example of what changing these settings do?  
> 
> I have only a layperson's understanding, so looking for help. 
> 
> Best, David.
>

Where is this QTR GUI page? I have looked every where. 

--- In QuadtoneRIP@yahoogroups.com, "Brian Ellis" <bellis60@...> wrote:
>
> From the "Help" tab at the top of the QTR Gui page:


Also, the documentation says to 

In Photoshop version CS2, select:
-Document: profile: gray gamma 2.2

Where do I go to change this, I cannot seem to find out where to do it. I read somewhere tht 
in CS2 that gamma is 2.2 by default, thanks, stephen w

Sorry: I am on a Mac. 
When I read further, It appears that Mac is set to 1.8 by default, but photoshop handles 
the image as 2.2: so my photographs are printing darker, Is that correct? How do I make 
them agree, and keep the image as 2.2 which is what QTR prefers?

thanks, sw

--- In QuadtoneRIP@yahoogroups.com, "Stephen Weiss" <stephenaweiss@...> wrote:
>
> Where is this QTR GUI page? I have looked every where. 
> 
> --- In QuadtoneRIP@yahoogroups.com, "Brian Ellis" <bellis60@> wrote:
> >
> > From the "Help" tab at the top of the QTR Gui page:
> 
> 
> Also, the documentation says to 
> 
> In Photoshop version CS2, select:
> -Document: profile: gray gamma 2.2
> 
> Where do I go to change this, I cannot seem to find out where to do it. I read somewhere 
tht 
> in CS2 that gamma is 2.2 by default, thanks, stephen w
>

I, too have had considerable problems using QTR.  The User guide admits
it is slightly out of date.  This sin't the problem.  But I am a user of
computers with considerable experience and have an advanced science
degree, and I find the description of the process of making a curve very
difficult to follow.  I am trying to make a curve to use Epson Premium
glossy Photo paper on an R800.  The values I get seem very different
from those given in the example.  And although I own an EyeOne, the
instructions for using it to get the values needed are sketchy to say
the least.  I followed along with the beginning of the tutorial and made
a new curve, and then attempted to print the step wedge, but the program
simply does not print my test.
Now, I fully expect to be removed from this list after less than 24
hours  of membership and my initial post, since the writer of this
initial post has been accused of whining about something rather than
making a sincere attempt to get help with a difficult process.
Please don't get me wrong about all this.  QTR is obviously worth
considerably more than the $50 shareware request.  Commercial RIPS are
exorbitantly expensive, and don't offer usage on smaller printers like
the R800.  But it is not simple to use.  I suggest that a list of
profiles by successful users of various printers might be a useful start
for those who wish to customize their curves.  And I respectfully
suggest that those of us with difficulties are not just complaining, but
asking for help from the more experienced and more knowledgeable.
--- In QuadtoneRIP@yahoogroups.com, "dlruckus" <dlruckus@...> wrote:
>
> Hello David. I will try to help but if anyone has better words, please
> chip in.
> Density, as it relates to QTR, means  how dark does the ink look once
> printed on the paper. It's the nature of the relationships between the
> inks and papers we use to vary with different printers,inks and papers
> and, to some extent, even in variations in the surrounding environment
> (eg: humidity,temperatures etc). It is also true that more ink does
> not necessarily mean darker. There often comes a point where the
> application of more ink to the paper actually makes it look lighter
> rather than darker. The use of the terms density and ink limits in QTR
> are referring to this effect. We all want the maximum darkness(d'max)
> as dark as possible so we try to limit the amount of ink used to be
> only just enough to give us the maximum visual blackness we can get.
> In practice, generally you stop somewhere just before this at a point
> where increasing the amount of ink laid down stops giving significant
> increases in density. You do Not want to go beyond that to where you
> reverse the ever increasing darkness curve.
> What I just described is in reference to the K ink but it is equally
> true of the lighter inks(grays). At some point they also will max out
> in their density and give no more. So when you make the calibration
> prints within QTR you are, first, trying to determine what the maximum
> amount of black ink you can use is(limit) and, second, once this is
> determined, testing for what the darkness of each of the other
> inks(grays) is at that same limit and specifically in relation to the
> black ink. Those figures are then used to derive the initial control
> points used for bringing the various shades in during the printing
> process so you get the proper distribution of tones.
> Linearizing is just a continuation of the above process by adjusting
> the curves that were derived from them such that they give equal steps
> across the test step tablet and replicate it properly.
>
> All said above is a simplification, though I believe accurate, of what
> the QTR RIP does and or can do. It has many controls and, beyond a few
> folks who post here, most of us don't have sufficient experience and
> knowledge of rips overall to be proclaiming much in the way of wisdom
> in the matter. That is why it sometimes takes a while to get suitable
> answers to questions. We don't really relish the possibility of being
> caught out as a case of the blind leading the blind. Most will wait to
> see if someone far more knowledgeable will answer first. Those people
> are usually very busy and have limited time to spend in doing so.
>
> In regards to this overall thread (Not your query), some of the
> responses or complaints are a bit like a 5 year old going into a rage
> because daddy won't teach him to drive the family sedan. Never mind
> that he's still too small to reach the pedals and can't yet read the
> road signs.
>
> Regards
> Duane
>
>
>
> --- In QuadtoneRIP@yahoogroups.com, "David" dkfreed@ wrote:
> >
> > I've posted this question before, but didn't really understand the
> > answers. So again, can someone help me understand what the ink
density

> > and ink limit settings do? How are they different, the same?  Can
> > someone give an example of what changing these settings do?
> >
> > I have only a layperson's understanding, so looking for help.
> >
> > Best, David.
> >
>

I agree abput the difficulties, and I wonder sometimes if the photographers on this board are putting the technical too much before the aesthetic.  I have not used QTR enough, but I imagine not so much of a ned to start customizng too much, since so many great printing papers have been profiled.  
   
  Between good inks and good papers, and most importantly good lighting and correct exposures... how much customing do we need?
   
  Again, I have not dug in enough to really say....but in the tradtional photo days...sometimes we got way too techy, and I sense this in the new processes.  Innovative ways of seeing, innovative compositions, and good exposures will prove to be more important then mapping out every print like a science experiment.
   
   

       
---------------------------------
Looking for a deal? Find great prices on flights and hotels with Yahoo! FareChase.

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

Hi John,

Your description of your qualifications and experience is similar to mine.

I found the best notes to follow were the help file, User guide by Tom Moore.  Where I ran into probems was my print out of the "Ink Test Separation Page" suggested the limit for the black was around 50%, while the article referring to the same printer suggested it was normally around 80% which I initially used.  I am using the Epson 2100 printer.

I use the Colorvision Printfixpro unit, and found this valuable for checking the maximum value, and now need to redo the calibration with this value.

However, after using the linearization process the test print came out excellently.  

I found it best to set up with the system for just 2 inks initially, then when this was working then experiment adding colours to remove the warm tone.  This enabled me to easily print warm, cool and neutral prints.  

If you have any queries on how I went about it e-mail me off list and I will try to help you.  I found initially I had so many sources of information it was confusing, and coming back to the Tom Moore paper was best.

Good luck

Jim Thyer

  ----- Original Message ----- 
  From: johncjmd 
  To: QuadtoneRIP@yahoogroups.com 
  Sent: Friday, September 21, 2007 8:08 AM
  Subject: [QuadtoneRIP] Re: In Curve Creation: understanding ink limit and ink density settings


  I, too have had considerable problems using QTR. The User guide admits
  it is slightly out of date. This sin't the problem. But I am a user of
  computers with considerable experience and have an advanced science
  degree, and I find the description of the process of making a curve very
  difficult to follow. I am trying to make a curve to use Epson Premium
  glossy Photo paper on an R800. The values I get seem very different
  from those given in the example. And although I own an EyeOne, the
  instructions for using it to get the values needed are sketchy to say
  the least. I followed along with the beginning of the tutorial and made
  a new curve, and then attempted to print the step wedge, but the program
  simply does not print my test.
  Now, I fully expect to be removed from this list after less than 24
  hours of membership and my initial post, since the writer of this
  initial post has been accused of whining about something rather than
  making a sincere attempt to get help with a difficult process.
  Please don't get me wrong about all this. QTR is obviously worth
  considerably more than the $50 shareware request. Commercial RIPS are
  exorbitantly expensive, and don't offer usage on smaller printers like
  the R800. But it is not simple to use. I suggest that a list of
  profiles by successful users of various printers might be a useful start
  for those who wish to customize ther curves. And I respectfully
  suggest that those of us with difficulties are not just complaining, but
  asking for help from the more experienced and more knowledgeable.
  --- In QuadtoneRIP@yahoogroups.com, "dlruckus" <dlruckus@...> wrote:
  >
  > Hello David. I will try to help but if anyone has better words, please
  > chip in.
  > Density, as it relates to QTR, means how dark does the ink look once
  > printed on the paper. It's the nature of the relationships between the
  > inks and papers we use to vary with different printers,inks and papers
  > and, to some extent, even in variations in the surrounding environment
  > (eg: humidity,temperatures etc). It is also true that more ink does
  > not necessarily mean darker. There often comes a point where the
  > application of more ink to the paper actually makes it look lighter
  > rather than darker. The use of the terms density and ink limits in QTR
  > are referring to this effect. We all want the maximum darkness(d'max)
  > as dark as possible so we try to limit the amount of ink used to be
  > only just enough to give us the maximum visual blackness we can get.
  > In practice, generally you stop somewhere just before this at a point
  > where increasing the amount of ink laid down stops giving significant
  > increases in density. You do Not want to go beyond that to where you
  > reverse the ever increasing darkness curve.
  > What I just described is in reference to the K ink but it is equally
  > true of the lighter inks(grays). At some point they also will max out
  > in their density and give no more. So when you make the calibration
  > prints within QTR you are, first, trying to determine what the maximum
  > amount of black ink you can use is(limit) and, second, once this is
  > determined, testing for what the darkness of each of the other
  > inks(grays) is at that same limit and specifically in relation to the
  > black ink. Those figures are then used to derive the initial control
  > points used for bringing the various shades in during the printing
  > process so you get the proper distribution of tones.
  > Linearizing is just a continuation of the above process by adjusting
  > the curves that were derived from them such that they give equal steps
  > across the test step tablet and replicate it properly.
  >
  > All said above is a simplification, though I believe accurate, of what
  > the QTR RIP does and or can do. It has many controls and, beyond a few
  > folks who post here, most of us don't have sufficient experience and
  > knowledge of rips overall to be proclaiming much in the way of wisdom
  > in the matter. That is why it sometimes takes a while to get suitable
  > answers to questions. We don't really relish the possibility of being
  > caught out as a case of the blind leading the blind. Most will wait to
  > see if someone far more knowledgeable will answer first. Those people
  > are usually very busy and have limited time to spend in doing so.
  >
  > In regards to this overall thread (Not your query), some of the
  > responses or complaints are a bit like a 5 year old going into a rage
  > because daddy won't teach him to drive the family sedan. Never mind
  > that he's still too small to reach the pedals and can't yet read the
  > road signs.
  >
  > Regards
  > Duane
  >
  >
  >
  > --- In QuadtoneRIP@yahoogroups.com, "David" dkfreed@ wrote:
  > >
  > > I've posted this question before, but didn't really understand the
  > > answers. So again, can someone help me understand what the ink
  density
  > > and ink limit settings do? How are they different, the same? Can
  > > someone give an example of what changing these settings do?
  > >
  > > I have only a layperson's understanding, so looking for help.
  > >
  > > Best, David.
  > >
  >



   

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

QTR is a great tool that is easy or difficult depending on what inkset,
printer and workflow one is using.

 

With the R1800/800 3-MK workflow (described further here:
http://www.paulroark.com/BW-Info/R1800.htm ), which has profiles included in
the just-released version of QTR, the same basic curves work for virtually
all matte papers.  To make a curve for a paper that is not already profiled
is, basically, a 2-step process:  determine the dmax and linearize the
results.  The instructions for how to do this are in the Notes tab of the
Dmax test and the Start profiles that are included in QTR.  

 

The procedure for the R260 using black only is essentially the same -
determine dmax with an included test curve and then linearize.

 

The learning curve can be steep and long, but it's worth it.  Start simple.

 

Paul

www.PaulRoark.com <http://www.paulroark.com/>  

 

 

 

 

. I find the description of the process of making a curve very difficult to
follow. . 



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

Hello John. My post is nearly a month old now. It could hardly have
been in reference to you. Most of it was an attempt,however poorly
done, to help David. It explicitly stated that his query was Not a
problem. It is true that the learning curve seems somewhat steep, as
others have mentioned.
 The last paragraph was an expression of opinion about the impatience
of some who, in reaction to their personal difficulties in
understanding, become highly critical of that which they don't
understand. Frustration can have that result with some. Not even the
highly learned are immune at times. Should you not agree with the
opinion, however, it is perfectly ignorable;-)
 As regards your problem. First, the paper and, if I'm not mistaken,
the printer you are using is designed specifically for glossy papers.
If you are referring to values from your spectro, they would be
expected to show high maximum densities for that situation. The
tutorials likely were written from data using matt papers and would
report different, and lower, density numbers. There's nothing
diabolical about that. It shouldn't be particularly objectionable or
difficult to understand either. 
 I have not looked to see if there are previously generated curves for
your printer in the QTR distribution but assume from your comments
that there are not. Asking if others may have made one for your
combination of paper and machine is the viable way to go. If you don't
receive a response to that then you are left with the prospect of
making your own. As a scientist, you should find it easy to adapt
virtually any glossy paper curve for any machine/ink combination that
IS included with QTR to your needs. The same is true for any matt
papers as well. Then "you" can be the respondent to another newbie
with the same query.
 I do not have, or have access to, an Eye-one so can't comment on that
issue.
 If your creation of a new curve was successful and you were able to
save it, then it should be available to you for use. If you found it
in the curve box in QTRgui and selected it before trying to print the
 step table through QTR you should have ended up with a print. You
apparently did not. If you are looking for help in finding out why
that is, you will need to give a lot more information on exactly how
you went about the task.
 Lastly, I doubt anyone has ever been tossed off for asking a
question. It would not be me doing the tossing in any case.

Regards
Duane
  

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

>
> I, too have had considerable problems using QTR.  The User guide admits
> it is slightly out of date.  This sin't the problem.  But I am a user of
> computers with considerable experience and have an advanced science
> degree, and I find the description of the process of making a curve very
> difficult to follow.  I am trying to make a curve to use Epson Premium
> glossy Photo paper on an R800.  The values I get seem very different
> from those given in the example.  And although I own an EyeOne, the
> instructions for using it to get the values needed are sketchy to say
> the least.  I followed along with the beginning of the tutorial and made
> a new curve, and then attempted to print the step wedge, but the program
> simply does not print my test.
> Now, I fully expect to be removed from this list after less than 24
> hours  of membership and my initial post, since the writer of this
> initial post has been accused of whining about something rather than
> making a sincere attempt to get help with a difficult process.
> Please don't get me wrong about all this.  QTR is obviously worth
> considerably more than the $50 shareware request.  Commercial RIPS are
> exorbitantly expensive, and don't offer usage on smaller printers like
> the R800.  But it is not simple to use.  I suggest that a list of
> profiles by successful users of various printers might be a useful start
> for those who wish to customize their curves.  And I respectfully
> suggest that those of us with difficulties are not just complaining, but
> asking for help from the more experienced and more knowledgeable.
> --- In QuadtoneRIP@yahoogroups.com, "dlruckus" <dlruckus@> wrote:
> >
> > Hello David. I will try to help but if anyone has better words, please
> > chip in.
> > Density, as it relates to QTR, means  how dark does the ink look once
> > printed on the paper. It's the nature of the relationships between the
> > inks and papers we use to vary with different printers,inks and papers
> > and, to some extent, even in variations in the surrounding environment
> > (eg: humidity,temperatures etc). It is also true that more ink does
> > not necessarily mean darker. There often comes a point where the
> > application of more ink to the paper actually makes it look lighter
> > rather than darker. The use of the terms density and ink limits in QTR
> > are referring to this effect. We all want the maximum darkness(d'max)
> > as dark as possible so we try to limit the amount of ink used to be
> > only just enough to give us the maximum visual blackness we can get.
> > In practice, generally you stop somewhere just before this at a point
> > where increasing the amount of ink laid down stops giving significant
> > increases in density. You do Not want to go beyond that to where you
> > reverse the ever increasing darkness curve.
> > What I just described is in reference to the K ink but it is equally
> > true of the lighter inks(grays). At some point they also will max out
> > in their density and give no more. So when you make the calibration
> > prints within QTR you are, first, trying to determine what the maximum
> > amount of black ink you can use is(limit) and, second, once this is
> > determined, testing for what the darkness of each of the other
> > inks(grays) is at that same limit and specifically in relation to the
> > black ink. Those figures are then used to derive the initial control
> > points used for bringing the various shades in during the printing
> > process so you get the proper distribution of tones.
> > Linearizing is just a continuation of the above process by adjusting
> > the curves that were derived from them such that they give equal steps
> > across the test step tablet and replicate it properly.
> >
> > All said above is a simplification, though I believe accurate, of what
> > the QTR RIP does and or can do. It has many controls and, beyond a few
> > folks who post here, most of us don't have sufficient experience and
> > knowledge of rips overall to be proclaiming much in the way of wisdom
> > in the matter. That is why it sometimes takes a while to get suitable
> > answers to questions. We don't really relish the possibility of being
> > caught out as a case of the blind leading the blind. Most will wait to
> > see if someone far more knowledgeable will answer first. Those people
> > are usually very busy and have limited time to spend in doing so.
> >
> > In regards to this overall thread (Not your query), some of the
> > responses or complaints are a bit like a 5 year old going into a rage
> > because daddy won't teach him to drive the family sedan. Never mind
> > that he's still too small to reach the pedals and can't yet read the
> > road signs.
> >
> > Regards
> > Duane
> >
> >
> >
> > --- In QuadtoneRIP@yahoogroups.com, "David" dkfreed@ wrote:
> > >
> > > I've posted this question before, but didn't really understand the
> > > answers. So again, can someone help me understand what the ink
> density
> > > and ink limit settings do? How are they different, the same?  Can
> > > someone give an example of what changing these settings do?
> > >
> > > I have only a layperson's understanding, so looking for help.
> > >
> > > Best, David.
> > >
> >
>