QTR-Quadtone RIP

--- In QuadtoneRIP@yahoogroups.com, "Tom Moore" <r.t.moore@...> wrote:
>
> maybe a few questions
> and further dialogue will help both of us understand this.
> 
> Do you use QTR-RGB-LAB (or QTR-Gray-LAB) space? If so how/when.
> Do you use QTR-RGB Matte Paper space (Gray equivalent)? If so 
how/when.
> 
> Perhaps if you describe your workflow to get a print matching your 
monitor,
> we would be able to discover where either you or I have
> misunderstood the
> process.

Hi Tom, 

I think I'm getting there, but to be sure, this is my current process:

1) capture the image in RAW (Canon)
2) convert it to TIF / AdobeRGB (Photoshop or Lightroom)
3) make sure the monitor is calibrated (Eye-One)
4) edit the image in AdobeRGB - nondestructively by using adjustment 
layers - NO softproofing
5) save the image as "edit" version 
6) save another version of the image as "print" version
7) flatten the "print" version, convert to grayscale, convert to 8 
bit) 
8) "convert profile" to Gray-LAB
9) save the "print" file (TIF)
10) use QTR curves are created following your user manual, using the 
Eye-One.
11) print the file using QTR 2.5 (Epson 2100, UT3D inks, usually on 
EEM or HPR) 
12) evaluate print under different light sources
13) if necessary, back to 4)

I was pretty happy with the result of this workflow when I started 
("perfect match"), but by now I'm starting to see glitches. Usually 
the print is indeed a bit "flatter" than on my monitor and the 
printed highlights are just a bit darker. 

This morning I tried once again the softproofing process as you 
described it, but now using the gray-matte, gray-photo, rgb-matte and 
rgb-photo profiles. And now indeed I find the flattening as you 
describe in you reply to Frans.

I think I do understand: the L values in the file will run from 0-
100, while on paper the contrast is reduced. The softproof-profiles 
mimick this.

Now my two remaining issues:

1) is a very operational one. I based my knowledge of the use of the 
icc profiles on the "gray-readme.doc" from Roy that comes with the 
profiles. Nowhere in this document reference is made to soft-
proofing. Instead, a much difference use of the profiles is 
advocated. I cite: 

"For Windows where it's necessary to save a tiff file, you should 
Convert to Profile using either Gray Matte Paper or Gray Photo 
Paper.  Then save the file for printing in QTRgui." 

I tried this approach in the beginning, with lousy results (match 
became worse), discussed this shortly with Roy on this forum and then 
discarded the use of it. Now I understand it's use to be meant 
completely different! I think the document should be revised (if I'm 
correct now).

2) Even correct soft-proofing is not actually addressing the 
difference in character of a monitor and a print. The brightness and 
contrast of the monitor and the amount of light falling on the print 
all influence the amount of light actually falling into your eye and 
chance the perception of the monitor and print. And I don't see why 
the soft-proofing is necessarily improving the situation. I can 
imagine situations (for instance when the monitor has a very bad 
contrast, lower than the print, soft-proofing INCREASES the mismatch 
between print and monitor. But perhaps this whole thing is just based 
on practical experience, without a solid scientific base???

Joost