QTR-Quadtone RIP

Hi all,

In view of the confusion we had lately on this forum on the different
QTR workflows, I decided to do a small experiment, comparing two
workflows.

Workflow 1
1) editing the image. I used both AdobeRGB and Gray Lab as workspaces,
without differences, and (at least to my understanding) the editing
workspace is of NO relevance here. Any workspace will do

2) softproofing the image with the gray-matte-paper icc profile
(setting: "preserve numbers"=OFF, "rendering intent"="relative
colorimatric", "blank point compensation"=ON, "simulate black ink"=ON)

3) flatten, convert to 8-bit grayscale

4) convert profile to "gray-lab" and save as tif

5) print the image with QTRGUI

Workflow 2
1) editing:  same as workflow 1

2) NO softproofing

3) flatten, convert to 8-bit grayscale, smae as workflow 1

4) convert profile to "gray-matte-paper" and save as tif

5) print the image with QTRGUI, same as workflow 1


The hypothesis for this experiment was that these workflows, although
different, are actually equivalent.

  It's hard to get the hard physical, quantitative evidence from the
results.  It would involve direct comparison of screen luminances with
print luminances and  I do have a spectrometer but I have currently no
idea how to directly compare emissive and reflective values.

Nevertheless a qualitative comparison DOES support the hypothesis. In WF
1, the softproofing lightens  the image, with respect to the original
image. So if ones edits with Softproofing "on", the actual image is a
bit darker. In WF2, the conversion of the image the gray-matte-paper,
darkens the image. This is NOT visible on the screen, since photoshop
compensates for this, but it can be checked with the eye-dropper: the
LAB values drop (or the K-values increase which is the same) after
conversion.

So in BOTH cases  a darker image is sent to the printer than the one
displayed on the screen.  My explanation is as follows:  the dynamic
range/contrast of paper is lower than that of a screen. Paper can
typically display L-values between 15 and 95.  So, especially in the
blacks there is quite some descrepancy between paper black and image
black.  Both WF1 and WF2 are ways to compensate for this. WF1 uses the
gray-matte-profile to compensate the screen-paper difference on the
screen, while WF2 compensates it in the printer.

WF2 is the workflow as advocated by Roy, WF1 is the one I (and some
others) use. But now my (preliminary, since based on incomplete
evidence) conclusion is that they lead to the same result. I personally
always could live better with the theoretical foundation of  WF1, but
now I think I understand that it's just a matter of taste.

Open for any comment and critique. For the ones more knowledgeable than
I: please check if I used the right settings for softproofing.

Joost









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

Joost & Others,
I do not want this to divert from your current question about the two 
workflows you mentioned, but I have a different approach and maybe 
someone can tell me if I am doing something wrong.

I have used QTR for so long for B&W that I do not even remember if I 
paid Roy Harrington for the privilege or not (Roy, if you read this 
and can go back in your records, please replay off line if your 
discover I have not paid).  It is well worth the small cost.

I have tried the methods you have listed and found that to me, much 
of this is not required for me to obtain quality prints.  I 
understand the word "quality" is in the eyes of the beholder, but I 
have had B&W prints in exhibitions that were printed using my method 
in QTR with no complaints from anyone.  Here is my most current 
method to achieve Black & White prints:

1) Keep my monitor calibrated (using Spyder)
2) Process image using Lightroom, CS3, & Photokit Sharpener.(All in 
Adobe RBG workspace)
2a. Use Lightroom to convert to B&W (Before this I used CS2 & Channel 
Mixer Adjustment Layer)
3) No SoftProofing (I have found that what I see no my monitor is 
very close to what prints out in QTR)
4) Save a TIF file, flatten image (I do NOT convert to 8 bit + image 
file retains the color channels)
5) Print image with QTR GUI

The only difference in my printing workflow between color & B&W is 
that for color I do not display the image in B&W in Lightroom & I 
print color through PhotoShop using the Epson driver.

As stated earlier, I have not seen any benefit of doing additional 
steps.  I use paper profiles I have obtained from other.

I am sure that since I do not have dosimeters nor other scientific 
methods of measuring the exact results, some of the additional steps 
could be beneficial, but I really cannot see it for my self right 
now.  Hope someone can enlighten me if I am really missing something 
here?

It seems that the only way to be sure, is for others to print the 
same exact image on the same exact papers using the different 
methods.  If that image could be posted so that other then would 
print the same image (without any alteration), then it could be 
determined if most other have the same result.  I am suggesting this 
to compare QTR processes to each other, NOT differneces in printer 
models.

Thanks!

Bruce
http://BruceVarner.com/
___________________________________________

--- In QuadtoneRIP@yahoogroups.com, "Joost Horsten" <j.h.j.h@...> 
wrote:
> 
> Hi all,
> 
> In view of the confusion we had lately on this forum on the 
different

> QTR workflows, I decided to do a small experiment, comparing two
> workflows..............
>
>Joost

--- In QuadtoneRIP@yahoogroups.com, "btvarner" <btvarner@...> wrote:
>
> Joost & Others,
> I do not want this to divert from your current question about the 
two 
> workflows you mentioned, but I have a different approach and maybe 
> someone can tell me if I am doing something wrong.
> 
> 1) Keep my monitor calibrated (using Spyder)
> 2) Process image using Lightroom, CS3, & Photokit Sharpener.(All in 
> Adobe RBG workspace)
> 2a. Use Lightroom to convert to B&W (Before this I used CS2 & 
Channel 
> Mixer Adjustment Layer)
> 3) No SoftProofing (I have found that what I see no my monitor is 
> very close to what prints out in QTR)
> 4) Save a TIF file, flatten image (I do NOT convert to 8 bit + 
image 
> file retains the color channels)
> 5) Print image with QTR GUI

Hi Bruce,

As can be inferred indirectly from my post and more directly from 
other posts on this forum, I don't belief their is no "correct" 
workflow. In the end, EXACTLY matching print and screen is dependent 
from several other circumstances than can be compensated by a wokflow 
(ambient light, absolute monitor brightness). If I compare your 
workflow with the two I have described, I THINK the difference is 
that you effectively work in a gamma 2.2 gray space, since as I 
recall this is the gray space linked to AdobeRGB and sRGB, but I may 
be mistaken. It will also depend how you have set up Photoshop 
(see "edit", "color settings" in PS CS2).

According to Ernst Dinkla in another thread, there is in practice 
littel difference between Gray-lab and gamma 2.2. So your findings 
would fit in that.

Joost

Joost: 

In general I also use your WF1.  But I edit with Pictrue Windows Pro 
using the softproofing QTR RGB icc profiles I generated from 
linearized QTRgui printouts of the QTR 21step wedges and a similiar 
rendering intent as you.  

1) In my case editing starts with 16-bit RGB images (usually in 
AdobeRGB) that I first convert to 16-bit BW using the Picture Windows 
equivalent of a channel mixer.  Conversion removes any profile tags.  
[Note the softproofing monitor image of the RGB image is BW.] 
2) Set B/W points and use curves (combinations of RGB, HSL, and HSV) 
to get the 16-bit on screen image I want.  
3) Resize for printing.
4) Sharpen as needed.
5) Use Neat Image to remove grain as needed.
6) Save the image as a 8-bit tiff image.
7) Print through QTRgui using the .Quad profile used to create the 
softproofing icc profile.  

Unlike your Step 4, I don't tag or convert my images to any profiles 
during my workflow--QTRgui seems to work just fine.

Jeff


--- In QuadtoneRIP@yahoogroups.com, "Joost Horsten" <j.h.j.h@...> 
wrote:
>
> 
> Hi all,
> 
> In view of the confusion we had lately on this forum on the 
different
> QTR workflows, I decided to do a small experiment, comparing two
> workflows.
> 
> Workflow 1
> 1) editing the image. I used both AdobeRGB and Gray Lab as 
workspaces,
> without differences, and (at least to my understanding) the editing
> workspace is of NO relevance here. Any workspace will do
> 
> 2) softproofing the image with the gray-matte-paper icc profile
> (setting: "preserve numbers"=OFF, "rendering intent"="relative
> colorimatric", "blank point compensation"=ON, "simulate black 
ink"=ON)
> 
> 3) flatten, convert to 8-bit grayscale
> 
> 4) convert profile to "gray-lab" and save as tif
> 
> 5) print the image with QTRGUI
> 
> Workflow 2
> 1) editing:  same as workflow 1
> 
> 2) NO softproofing
> 
> 3) flatten, convert to 8-bit grayscale, smae as workflow 1
> 
> 4) convert profile to "gray-matte-paper" and save as tif
> 
> 5) print the image with QTRGUI, same as workflow 1
> 
> 
> The hypothesis for this experiment was that these workflows, 
although
> different, are actually equivalent.
> 
>   It's hard to get the hard physical, quantitative evidence from the
> results.  It would involve direct comparison of screen luminances 
with
> print luminances and  I do have a spectrometer but I have currently 
no
> idea how to directly compare emissive and reflective values.
> 
> Nevertheless a qualitative comparison DOES support the hypothesis. 
In WF
> 1, the softproofing lightens  the image, with respect to the 
original
> image. So if ones edits with Softproofing "on", the actual image is 
a
> bit darker. In WF2, the conversion of the image the gray-matte-
paper,
> darkens the image. This is NOT visible on the screen, since 
photoshop
> compensates for this, but it can be checked with the eye-dropper: 
the
> LAB values drop (or the K-values increase which is the same) after
> conversion.
> 
> So in BOTH cases  a darker image is sent to the printer than the one
> displayed on the screen.  My explanation is as follows:  the dynamic
> range/contrast of paper is lower than that of a screen. Paper can
> typically display L-values between 15 and 95.  So, especially in the
> blacks there is quite some descrepancy between paper black and image
> black.  Both WF1 and WF2 are ways to compensate for this. WF1 uses 
the
> gray-matte-profile to compensate the screen-paper difference on the
> screen, while WF2 compensates it in the printer.
> 
> WF2 is the workflow as advocated by Roy, WF1 is the one I (and some
> others) use. But now my (preliminary, since based on incomplete
> evidence) conclusion is that they lead to the same result. I 
personally
> always could live better with the theoretical foundation of  WF1, 
but
> now I think I understand that it's just a matter of taste.
> 
> Open for any comment and critique. For the ones more knowledgeable 
than

> I: please check if I used the right settings for softproofing.
> 
> Joost
> 
> 
> 
> 
> 
> 
> 
> 
> 
> [Non-text portions of this message have been removed]
>

In Step 1 I should have said I start with 48-bit RGB images and that 
the softproofing monitor image of the RGB image is "toned" BW -- 
otherwise why softproof with an RGB icc profile? :)

--- In QuadtoneRIP@yahoogroups.com, "Jeff Randall" <jrandall@...> 
wrote:
>
> Joost: 
> 
> In general I also use your WF1.  But I edit with Pictrue Windows 
Pro 
> using the softproofing QTR RGB icc profiles I generated from 
> linearized QTRgui printouts of the QTR 21step wedges and a similiar 
> rendering intent as you.  
> 
> 1) In my case editing starts with 16-bit RGB images (usually in 
> AdobeRGB) that I first convert to 16-bit BW using the Picture 
Windows 
> equivalent of a channel mixer.  Conversion removes any profile 
tags.  
> [Note the softproofing monitor image of the RGB image is BW.] 
> 2) Set B/W points and use curves (combinations of RGB, HSL, and 
HSV) 
> to get the 16-bit on screen image I want.  
> 3) Resize for printing.
> 4) Sharpen as needed.
> 5) Use Neat Image to remove grain as needed.
> 6) Save the image as a 8-bit tiff image.
> 7) Print through QTRgui using the .Quad profile used to create the 
> softproofing icc profile.  
> 
> Unlike your Step 4, I don't tag or convert my images to any 
profiles 
> during my workflow--QTRgui seems to work just fine.
> 
> Jeff
> 
> 
> --- In QuadtoneRIP@yahoogroups.com, "Joost Horsten" <j.h.j.h@> 
> wrote:
> >
> > 
> > Hi all,
> > 
> > In view of the confusion we had lately on this forum on the 
> different
> > QTR workflows, I decided to do a small experiment, comparing two
> > workflows.
> > 
> > Workflow 1
> > 1) editing the image. I used both AdobeRGB and Gray Lab as 
> workspaces,
> > without differences, and (at least to my understanding) the 
editing
> > workspace is of NO relevance here. Any workspace will do
> > 
> > 2) softproofing the image with the gray-matte-paper icc profile
> > (setting: "preserve numbers"=OFF, "rendering intent"="relative
> > colorimatric", "blank point compensation"=ON, "simulate black 
> ink"=ON)
> > 
> > 3) flatten, convert to 8-bit grayscale
> > 
> > 4) convert profile to "gray-lab" and save as tif
> > 
> > 5) print the image with QTRGUI
> > 
> > Workflow 2
> > 1) editing:  same as workflow 1
> > 
> > 2) NO softproofing
> > 
> > 3) flatten, convert to 8-bit grayscale, smae as workflow 1
> > 
> > 4) convert profile to "gray-matte-paper" and save as tif
> > 
> > 5) print the image with QTRGUI, same as workflow 1
> > 
> > 
> > The hypothesis for this experiment was that these workflows, 
> although
> > different, are actually equivalent.
> > 
> >   It's hard to get the hard physical, quantitative evidence from 
the
> > results.  It would involve direct comparison of screen luminances 
> with
> > print luminances and  I do have a spectrometer but I have 
currently 
> no
> > idea how to directly compare emissive and reflective values.
> > 
> > Nevertheless a qualitative comparison DOES support the 
hypothesis. 
> In WF
> > 1, the softproofing lightens  the image, with respect to the 
> original
> > image. So if ones edits with Softproofing "on", the actual image 
is 
> a
> > bit darker. In WF2, the conversion of the image the gray-matte-
> paper,
> > darkens the image. This is NOT visible on the screen, since 
> photoshop
> > compensates for this, but it can be checked with the eye-dropper: 
> the
> > LAB values drop (or the K-values increase which is the same) after
> > conversion.
> > 
> > So in BOTH cases  a darker image is sent to the printer than the 
one
> > displayed on the screen.  My explanation is as follows:  the 
dynamic
> > range/contrast of paper is lower than that of a screen. Paper can
> > typically display L-values between 15 and 95.  So, especially in 
the
> > blacks there is quite some descrepancy between paper black and 
image
> > black.  Both WF1 and WF2 are ways to compensate for this. WF1 
uses 
> the
> > gray-matte-profile to compensate the screen-paper difference on 
the
> > screen, while WF2 compensates it in the printer.
> > 
> > WF2 is the workflow as advocated by Roy, WF1 is the one I (and 
some
> > others) use. But now my (preliminary, since based on incomplete
> > evidence) conclusion is that they lead to the same result. I 
> personally
> > always could live better with the theoretical foundation of  WF1, 
> but
> > now I think I understand that it's just a matter of taste.
> > 
> > Open for any comment and critique. For the ones more 
knowledgeable 

> than
> > I: please check if I used the right settings for softproofing.
> > 
> > Joost
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > 
> > [Non-text portions of this message have been removed]
> >
>