QTR-Quadtone RIP

If I use your QIDF file for 3MK with the MK PK and GLOP positions and 
want to put the third Eboni ink in the Y position, I understand that I 
change LIMIT_Y to equal 70 and LIMIT_GL to equal blank , and change 
UNUSED_INK_3 to equal GL; also that CURVE_GL is changed to CURVE_Y, 
but do I keep Linearize as is for the first scan or delete that info?

Sorry to be so dim.

Thanks,

Colin

Colin,

>If I use your QIDF file for 3MK with the MK PK and GLOP positions and 
>want to put the third Eboni ink in the Y position, I understand that I 
>change LIMIT_Y to equal 70

I use the Windows Curve Creator GUI and have to scroll down in the Yellow
window to "Load Curve" first.

> and LIMIT_GL to equal blank ,

When I open the file with Notepad, I see the terms you're changing, and that
seems correct.

In the Windows Curve Creator, after you copy the curve over, scroll down in
that window and put "Not Used" in the box.

>and change UNUSED_INK_3 to equal GL;

As I use the Curve Creator, I'm not 100% clear here, but it looks like the
Unused_Ink order might call for them to be in order C, M, R, B, and then GL.
So, GL would be UNUSED_INK_5=GL.  

>also that CURVE_GL is changed to CURVE_Y, 

Again, I'm not sure if the program is sensitive to the order, but it may be
that the CURVE_Y ... needs to be between the MK and PK curves.

In the Curve Creator, I'd just copy the GL numbers and paste them into the Y
points list.

>but do I keep Linearize as is for the first scan or delete that info?

If you are going to re-linearize the profile, then I'd eliminate the
linearization data for the test strip you'll print.  You might want to see
if the same linearization still works.  It has on my 1800 when I've changed
the ink positions.  I've heard on some others, however, that they needed
some re-linearization. 

Hope this helps.

Paul
www.PaulRoark.com

--- In QuadtoneRIP@yahoogroups.com, "Paul Roark" <paul.roark@...> 
wrote:
>

> In the Curve Creator, I'd just copy the GL numbers and paste them 
into the Y
> points list.
> 
>> Hope this helps.
> 
> Paul
> www.PaulRoark.com
>
Thank you Paul for your response.

I have prepared QTR qidf files for HPR from your 3MK-Dmax-test 
through to re-linearizing using 67% and your 70% figure for the 
calculation of the end point; also I have copied the curves in the 
QIDF profile that you published for that paper.  In each case I do 
not get a linear curve but one that is like a gaussian curve but  
asymptotic toward the darker end, with the curve being too light.  
You should be able to generate the curve I get from using your HPR 
profile:


L	equal steps
95.43	95.43
92.31	91.67
89.29	87.91
86.04	84.14
82.87	80.38
79.73	76.62
76.93	72.86
74.26	69.09
72.07	65.33
69.67	61.57
67.26	57.81
64.93	54.04
61.81	50.28
57.67	46.52
53.06	42.76
47.61	38.99
41.88	35.23
35.50	31.47
29.85	27.71
26.08	23.94
20.18	20.18
 My spectrometer, the X-rite pulse elite measures L values, and 
these are in the first column.  The second equally divides the steps 
between Lmin and Lmax.  These can be plotted in a spreadsheet to 
illustrate the re-linearized curve.  Lmin of 20.18 is, I understand, 
equivalent to a Dmax of 1.65.

The mid point L value is 67.26 whereas, I presume it should be about 
57.8.

I have tried using the Ink Limit and Gamma sliders but cannot 
achieve a linear curve.  By adjusting the ink limits, the Dmax 
worsens.

Can you help me please?

Incidentally, I printed the 3MK-Dmax-test for Eboni in the MK, PK 
and Y slots separately, but at 100%, to check that my modifications 
were working correctly.  I was surprised to attain Dmax figures of 
1.76.  Can such a figure be obtained in practice.

Colin

Hi Colin,

I'd recommend you try the existing profile with just the ink positions
changed and see if it works for you.

>I have prepared QTR qidf files for HPR from your 3MK-Dmax-test 
>through to re-linearizing using 67% and your 70% figure for the 
>calculation of the end point;

It's probably unfortunate that my profiles use the 70 ink limit.  That was a
bit arbitrary and based on the very high loads I found I needed for some
un-coated papers to hit their dmax.  Note that the real action is setting
the end points in the curve creator -- at 38 for HPR.  So, 3 channels at 38
X 0.7 for an actual 26.6 per channel is an effective total ink limit of
79.8.

Note that the Dmax test is just for setting this end point for each curve.
It uses straight line curves that do not make for a good final curve at all.

After the dmax is determined, go to the 3MK-Start profile to print the test
strip for linearization -- after you've set the end points of the curves.
The Notes tab in that profile also has the instructions.  

All the profiles use about the same curves.  The ends are the only places
where things vary a bit due to different end points and the need to have a
smooth curve leading up to that point.  With the Windows Curve Creator and
its curve preview this is easy to do.  I'm not sure what the Mac situation
is.  If you don't have a preview, it's going to be hard to make good curves
from scratch.  Again, I'd just use the HPR curves I made.  Even if you're
dmax point is slightly different, it's probably close enough that only a
minor adjustment of the very end point will be needed.

I'm not sure where your 67% is coming from.

> also I have copied the curves in the 
>QIDF profile that you published for that paper. In each case I do 
>not get a linear curve ...

Again, I'd try the existing profile with just the ink positions changed
first. I can't tell what has gone wrong with your efforts.

>...

>... I was surprised to attain Dmax figures of 
>1.76. Can such a figure be obtained in practice.

Yes.  

(By the way, this system can also make the best Arches Hot Press (uncoated
watercolor paper) image I've seen with an inkjet, attaining up to a 1.6 dmax
with at paper -- rather high for an un-coated paper.)

Paul
www.PaulRoark.com

--- In QuadtoneRIP@yahoogroups.com, "Paul Roark" <paul.roark@...> 
wrote:
>
> Hi Colin,
> 
> I'd recommend you try the existing profile with just the ink 
positions
> changed and see if it works for you.

Paul. That is what I did last of all and the L values I put in my 
email was from that curve. (Apologies for my senior moment - I meant 
asymmetrical!)
> 
> >I have prepared QTR qidf files for HPR from your 3MK-Dmax-test 
> >through to re-linearizing using 67% and your 70% figure for the 
> >calculation of the end point;
> 
> It's probably unfortunate that my profiles use the 70 ink limit.  
That was a
> bit arbitrary and based on the very high loads I found I needed 
for some
> un-coated papers to hit their dmax.  Note that the real action is 
setting
> the end points in the curve creator -- at 38 for HPR.  So, 3 
channels at 38
> X 0.7 for an actual 26.6 per channel is an effective total ink 
limit of
> 79.8.
Yes, that is what I have from using your profile. 

> With the Windows Curve Creator and
> its curve preview this is easy to do.

I am using Win XP and it is easy to make the curve smoother at the 
right hand end. 

> (By the way, this system can also make the best Arches Hot Press 
(uncoated
> watercolor paper) image I've seen with an inkjet, attaining up to 
a 1.6 dmax
> with at paper -- rather high for an un-coated paper.)


I am in the UK and I know of no supplier for this paper.  Anyway I 
have stocks of HPR, Kayenta, William turner and Photo Rag Satin 
(horrible paper except for single chnnel BO - I haven't tried it on 
thr r1800).

I just need to know how to get the curve linear.

Colin  

> 
> Paul
> www.PaulRoark.com
>

Colin,

>> I'd recommend you try the existing profile with just the 
>> ink positions changed and see if it works for you.

> That is what I did last of all and the L values 
> I put in my email was from that curve. 

...
> I am using Win XP and it is easy to make the curve smoother 
> at the right hand end. 

>I just need to know how to get the curve linear.


OK, so you have my HPR profile with the ink positions altered to match your
printer setup.  To re-linearize the profile for your system, clear the
values in the Linearization tab and save it with a name that does not
overwrite a previous file. (I leave the sliders in the various tabs in their
default positions.) Then print a 21-step test file with the new profile that
has no linearization data in it.  Read the test print and insert the L
values into the Linearization table.

I didn't graph the L values in your previous post, but at least they seem to
be in order.  I'm not sure why you'd be getting such a low dmax.  Optimizing
the dmax with that profile I call Dmax-test is the first thing I do when
profiling a paper with the 3MK setup.  With HPR you should be seeing L
values for the dmax in the 14 to 15 range.

I hope this helps.  If I've misunderstood the issue, let me know.

Paul
www.PaulRoark.com

--- In QuadtoneRIP@yahoogroups.com, "Paul Roark" <paul.roark@...> 
wrote:
>
> 
> OK, so you have my HPR profile with the ink positions altered to 
match your
> printer setup.  To re-linearize the profile for your system, clear 
the
> values in the Linearization tab and save it with a name that does 
not
> overwrite a previous file. (I leave the sliders in the various 
tabs in their
> default positions.) Then print a 21-step test file with the new 
profile that
> has no linearization data in it.  Read the test print and insert 
the L
> values into the Linearization table.
> 
> Paul
> www.PaulRoark.com
>
Paul 

Thanks for your help.

I copied your qidf file, gave it a new name, modified the data for 
my ink positions and deleted the linearization data.   In order to 
print the step wedge using this file I also copied your original 
quad file and gave it the same name as the qidf file.  Was this 
correct?

I printed the unlinearized step wedge and, after hair dryer blowing, 
had an Lmin of 15.92 (Dmax 1.75)

I inserted the scanned data and `relinearized'.  Lmin was 16.82 
(Dmax 1.73)

The curve was not linear. You can see this from the linearized 
data.  The first column takes the Lmin and Lmax values from the 
second column which are the scanned L values and calculates equal 
steps between these.  These values therefore decreases linearly.  
Plotting, as a line graph, the first column against the second 
column with the L values shows the curve shape, which is far from 
linear.  It looks as though the ink limit had been set to a high 
negative value, but it, and the gamma value were both set at zero.  
The third and fourth columns are the `a, and `b' values.


Equal steps            L                    a                 b
95.63	95.63	0.62	0.46
91.69	91.83	0.67	0.77
87.75	88.35	0.72	1.07
83.81	84.30	0.85	1.34
79.87	80.70	0.91	1.49
75.93	77.78	1.00	1.67
71.99	75.34	1.08	1.71
68.05	72.58	1.12	1.92
64.11	70.54	1.13	2.05
60.17	67.97	1.16	2.21
56.23	65.90	1.21	2.36
52.28	63.85	1.26	2.29
48.34	60.82	1.24	2.58
44.40	57.34	1.23	2.71
40.46	53.85	1.38	2.78
36.52	49.65	1.48	2.76
32.58	44.40	1.51	3.03
28.64	39.28	1.51	2.96
24.70	33.45	1.57	2.93
20.76	26.70	1.46	2.58
16.82	16.82	0.72	1.08


Any ideas as to what I am doing wrong?


Colin

Colin,

...

>I copied your qidf file, gave it a new name, modified the data for 
>my ink positions and deleted the linearization data. 

That sounds correct.

>In order to 
>print the step wedge using this file I also copied your original 
>quad file and gave it the same name as the qidf file. 
>Was this correct?

I don't think so.  My original *.quad file would have the linearization data
reflected in it, I believe.  If you'd saved the *.qidf file with the
linearization data removed, it'd make a new quad file.  This new file is
what should have been used for linearization.  On the other hand, if you
saved the new qidf file, it probably overwrote the old quad file.

>I printed the unlinearized step wedge and, 

Maybe it was unlinearized -- maybe not if my original quad file was still
there and unaltered.


> after hair dryer blowing, had an Lmin of 15.92 (Dmax 1.75)

At least you've got a good dmax now.

>I inserted the scanned data and `relinearized'. 
>Lmin was 16.82 (Dmax 1.73)

Linearization should not affect the end points.  This is probably a random
difference.

If, however, you "reliniearized" but from a print produced by the quad file
that already had my linearized numbers reflected in it, that might be the
problem.


>The curve was not linear. You can see this from the linearized 
>data. 

The second column is clearly not linear.

>The first column takes the Lmin and Lmax values from the 
>second column which are the scanned L values and calculates equal 
>steps between these.

I simply open the spectro's text file output (I now use the
ColorVision/DataColor spectro, in part due to it's output format relative to
my old X-Rite) in Excel and graph it (Insert>Chart>Line).  A linearized QTR
output should be a nice straight line.

I use these Excel graphs a lot.  When I'm making a curve in either QTR or
Photoshop (usually for dropping into QTR's Create ICC-RGB), I work from
these graphs (printed) and a simple ruler line on the paper.  The visual
feedback is very easy to use in changing the curve numbers.  The closer the
curve is to "linear" (where QTR is used for printing) or the gray gamma 2.2
space output (for ICC printing), the more likely that curve will make a good
linearized output -- and for almost all papers with little alteration.  If
the curve's cross-overs are well done for one paper, they are almost always
close enough to linearize well for all papers.  With QTR it may look like
I've made all sorts of different curves -- not so.  They are almost always
the same basic curve re-linearized for the new paper (from the raw, curve,
however, with previous linearization data removed).  With QTR I also look at
the end point for optimizing dmax.  For ICCs I just accept the Epson driver
limit, and it's often very close to optimum (but not always -- one area
where the rip can sometimes show a clear advantage even with an inkset that
is compatible with the Epson driver).

> ... It looks as though the ink limit had been set to a high 
>negative value, ...

I don't think it's an ink limit issue.  You would not be getting those good
dmax (Lmin) numbers if it were too low, and there would be a posterization
if it were too high.

See if your modified qidf file overwrote my quad file numbers or if you
were, in effect, doing a double linearization.

Paul
www.PaulRoark.com

I'm using 2.6.0 with Aperture on an iMac running
Leopard.  Printing to an R1800 using the 3MK ink set.

I was running off a pile of prints last night and
everything worked fine.

Tonight I sit down to continue printing and no go...no
output.  Watching the Mac's Activity Monitor I see no
sign of life from QTR.  Odd, I say to myself.  It's
like it doesn't know QTR is there.

I go to
Applications\QuadToneRIP\Profiles\R800-R1800-3MK and
run InstallR1800-3MK.command.  The script runs and I
see that it installs the the existing list of profiles
plus the new one I made a few days ago.

Back to Aperture, but it still won't print.  When the
print dialog comes up, I can bring up the QTR dialog
and select the profile I want along with the other
print parameters...it just doesn't do anything when I
click Print for the final time to send the image to
the printer.

What am I missing?  I know it's going to be something
really simple, and I'll be embarrassed, but I'm
willing to suffer some in order to finish my print job
on time.

Thanks in advance for any assistance.

Ken

Ha!  Don't know how or why  it happened, but it's
working again!  Obviously a case of "operator
malfunction"!

Ken


--- Ken Alexander <k.alexander@...> wrote:

> I'm using 2.6.0 with Aperture on an iMac running
> Leopard.  Printing to an R1800 using the 3MK ink
> set.
> 
> I was running off a pile of prints last night and
> everything worked fine.
> 
> Tonight I sit down to continue printing and no
> go...no
> output.  Watching the Mac's Activity Monitor I see
> no
> sign of life from QTR.  Odd, I say to myself.  It's
> like it doesn't know QTR is there.
> 
> I go to
> Applications\QuadToneRIP\Profiles\R800-R1800-3MK and
> run InstallR1800-3MK.command.  The script runs and I
> see that it installs the the existing list of
> profiles
> plus the new one I made a few days ago.
> 
> Back to Aperture, but it still won't print.  When
> the
> print dialog comes up, I can bring up the QTR dialog
> and select the profile I want along with the other
> print parameters...it just doesn't do anything when
> I
> click Print for the final time to send the image to
> the printer.
> 
> What am I missing?  I know it's going to be
> something
> really simple, and I'll be embarrassed, but I'm
> willing to suffer some in order to finish my print
> job
> on time.
> 
> Thanks in advance for any assistance.
> 
> Ken
> 
> 
> 
> 
> ------------------------------------
> 
> Yahoo! Groups Links
> 
> 
> 
> 
>

--- In QuadtoneRIP@yahoogroups.com, "Paul Roark" <paul.roark@...> 
wrote:
>
> Colin,
> 
> ...
> >In order to 
> >print the step wedge using this file I also copied your original 
> >quad file and gave it the same name as the qidf file. 
> >Was this correct?
> 
> I don't think so.  My original *.quad file would have the 
linearization data
> reflected in it, I believe.  If you'd saved the *.qidf file with 
the
> linearization data removed, it'd make a new quad file.  This new 
file is
> what should have been used for linearization.  On the other hand, 
if you
> saved the new qidf file, it probably overwrote the old quad file.
> 
> >I printed the unlinearized step wedge and, 
> 
> Maybe it was unlinearized -- maybe not if my original quad file 
was still
> there and unaltered.
> 
> Paul
> www.PaulRoark.com
>
Paul,

I must apologize that I am so dense but I cannot seem to get this 
right and my ignorance is at the root of this.  For example I don't 
know what the QUAD file is, what it is for, how it works, nor that 
it is important that I should.

If I take the QIDF file, strip it of the linearized points in 
notepad and save it with another name, the saved file is a txt 
file.  So I copy the QIDF file copy it and rename it and then strip 
out the linearized points and save it.  If I then press the show 
curve button and save it, no quad file of the same name is produced.

I need a QUAD file for Curve 1 in Curve Setup.  Using `none' yields  
an error message regarding the qdensity.

I have tied various QUAD files as models, the latest being 3MK-
Start.  But this, presumably, was designed for the third Eboni in 
the Glop position, not in the yellow position.  

I therefore investigated the MK-Start QUAD file, copied it, renamed 
it to be the same as the first part of the QIDF file.  I then put 
all the numbers in the GLOP part of that QUAD  file over the zeros 
in the yellow part of the file.  I then copied all the zeros in the 
red part of the file and copied them over the Glop numbers.  I then 
used this file in Curve Setup.

The resulting file, after relinearization was a significant 
improvement over what had been achieved before, but still not linear 
although Dmax is 1.75, as follows:

Equal Steps	L
95.54	95.54
91.57	92.26
87.60	89.43
83.63	86.02
79.66	82.60
75.69	78.81
71.72	75.13
67.75	71.03
63.78	67.17
59.81	63.10
55.84	58.84
51.86	54.12
47.89	49.34
43.92	44.63
39.95	39.90
35.98	34.37
32.01	29.33
28.04	24.68
24.07	20.92
20.10	18.06
16.13	16.13
I tried using the Ink Limit and Gamma sliders but without success 
and the Dmax worsened.  Have you any suggestions to generating the 
Quad file properly and getting a linear result?

Colin

Colin,
 
> ...
>If I take the QIDF file, strip it of the linearized 
>points in notepad 

Why are you working in Notepad?  In the Curve Creator all you need to do is
go to the Linearization tab and hit the Clear button at the bottom.  You
never really need to use Notepad or worry about the *.quad files, which are
stored in the \QuadTone folder.

>... If I then press the show curve button and save it, no quad file 
>of the same name is produced.

Be sure you're saving the file to the right folder -- R1800-3mk.  If so,
there should be a quad file produced in the similar QuadTone folder.  If the
profile shows up in the Curves list on the main GUI, a quad file was
produced.

>I need a QUAD file for Curve 1 in Curve Setup.

Yes.

>I have tied various QUAD files as models, ...

Just ignore them and work with the *.qidf files that you've opened in the
Curve Creator.  The program will take care of the *.quad files.

>I ... investigated the MK-Start QUAD file, copied it, 
>renamed it to be the same as the first part of the QIDF file. ...

Do essentially this same thing, but with the Curve Creator and the Start
file it opens.  Don't use Notepad or mess directly with the *.quad files.  

When you re-name and save the *.qidf file, BE SURE it's in the right folder.
That is a mistake I've made and missed occasionally, which then causes the
profile I think I just made to not show up on the list in the main GUI --
because I forgot to check the folder I was saving to.  Just because you open
a file from the 1800-3mk doesn't mean this program will save to that folder.
It tends to save to the 1800 folder instead.  So, you have to be real
careful to be sure you're saving to the right folder.  

Paul
www.PaulRoark.com

Paul,

At 0300 hours this morning I realized how to convert your QIDF and 
QUAD files to my changed printing channels using Notepad as I 
described earlier.  I did this, today, with your files  and the result 
was a beautiful linear plot requiring no further adjustment and a Dmax 
of 1.78.  I next tried your Kayenta profile and, with slight slider 
changes to Ink Limits and Gamma have a very good result with a Dmax of 
1.75.  I was going to profile William Turner following your 
suggestions but my printer refuses to give me a clear nozzle checks!

Many thanks, I feel as though I am on my way now, if the printer 
behaves.

Colin