QTR-Quadtone RIP

I have been using the QTR to get rid of the green color cast when printing on my Epson 
R2400. I have making neutral prints and am no interested in toning them. To that end, I have 
only been using the neutral curve. I am wondering why I normally have to adjust levels by 
about 10-15 points in the negative and also use curves to increase contrast to get my prints 
to look right, when with the Epson driver my prints are pretty close matches to what I see on 
my calibrated seen (albeit with the green color cast). Should I be mixing at least 2 curves, like 
50 cold and 50 warm to get neutral instead?

Thank you.

Frankly, I'm a bit puzzled by what you try to tell us, I conclude 
that QTR resolves your "green" issue but that the brightness/contrast 
do not match your screen image. Right?

First question: did you read Tom Moore's user guide. Second question, 
following that: did you convert your file to either Gray Lab or or 
RRGB lab?. If not then most likely your file is in either AdobeRGB or 
sRGB. This will give wrong results as QTR assumes an image in Lab 
color space.

Joost


--- In QuadtoneRIP@yahoogroups.com, "dellicson" <davinellicson@...> 
wrote:
>
> I have been using the QTR to get rid of the green color cast when 
printing on my Epson 
> R2400. I have making neutral prints and am no interested in toning 
them. To that end, I have 
> only been using the neutral curve. I am wondering why I normally 
have to adjust levels by 
> about 10-15 points in the negative and also use curves to increase 
contrast to get my prints 
> to look right, when with the Epson driver my prints are pretty 
close matches to what I see on 
> my calibrated seen (albeit with the green color cast). Should I be 
mixing at least 2 curves, like 

> 50 cold and 50 warm to get neutral instead?
> 
> Thank you.
>

Joost,

I've been printing from a 15% dot gain profile. I converted to QTR Gray Lab and the print 
looks the same. Also, there is always going to be a bit of difference from what I see on 
screen, hence the need for soft proofing and making adjustments before printing, right? 
Also, I am using the stock QTR Velvet Fine Art profile for my Hahnemuhle Natural Art Duo 
Matte paper and have not made custom profiles. QTR allows for much more gradation of 
tone than the standard Epson driver and it seems that's why I seem to need to darken 
and/or up the contrast a bit to keep the look I want. Does this sound right?

Thanks again.

Davin Ellicson





--- In QuadtoneRIP@yahoogroups.com, "Joost Horsten" <j.h.j.h@...> wrote:

>
> Frankly, I'm a bit puzzled by what you try to tell us, I conclude 
> that QTR resolves your "green" issue but that the brightness/contrast 
> do not match your screen image. Right?
> 
> First question: did you read Tom Moore's user guide. Second question, 
> following that: did you convert your file to either Gray Lab or or 
> RRGB lab?. If not then most likely your file is in either AdobeRGB or 
> sRGB. This will give wrong results as QTR assumes an image in Lab 
> color space.
> 
> Joost
> 
> 
> --- In QuadtoneRIP@yahoogroups.com, "dellicson" <davinellicson@> 
> wrote:
> >
> > I have been using the QTR to get rid of the green color cast when 
> printing on my Epson 
> > R2400. I have making neutral prints and am no interested in toning 
> them. To that end, I have 
> > only been using the neutral curve. I am wondering why I normally 
> have to adjust levels by 
> > about 10-15 points in the negative and also use curves to increase 
> contrast to get my prints 
> > to look right, when with the Epson driver my prints are pretty 
> close matches to what I see on 
> > my calibrated seen (albeit with the green color cast). Should I be 
> mixing at least 2 curves, like 
> > 50 cold and 50 warm to get neutral instead?
> > 
> > Thank you.
> >
>

--- In QuadtoneRIP@yahoogroups.com, "dellicson" <davinellicson@...> 
wrote:
>
> Joost,
> 
> I've been printing from a 15% dot gain profile. I converted to QTR 
Gray Lab and the print looks the same. 

I do not know how the 15% dot gain profile and the gray lab profile 
exactly compare, but they are different. "the same" is always a bit a 
tricky statement, it took me some time to appreciate some 
differences.   

> Also, there is always going to be a bit of difference from what I 
see on 
> screen, hence the need for soft proofing and making adjustments 
before printing, right? 

Yes and no. My experience is that I get a decent to good print in one 
go if the image is of average tonal character(not very light, not 
very dark). If I'm very critical I usually need 2-4 iterations to get 
it exactly right. But we're talking subtle differences here.

A question suddenly pops up: it should go without saying, but is your 
screen decently calibrated? If not, drop everything you're doing and 
fix that.

> Also, I am using the stock QTR Velvet Fine Art profile for my 
Hahnemuhle Natural Art Duo 
> Matte paper and have not made custom profiles. 

Ah... this might be key problem. You can't just take a QTR curve of 
one paper and use it for another. You just need a QTR curve for each 
specific combo of printer/inkset/paper.... I you do not want to go 
into curve creation yet, I suggest you purchase some paper that is 
already supported. I find Epson Enhanced/Archival Matte a good test 
paper (not for final prints as it is non-archival, no matter its 
name).

Good luck

Joost





QTR allows for much more gradation of 
> tone than the standard Epson driver and it seems that's why I seem 
to need to darken 
> and/or up the contrast a bit to keep the look I want. Does this 
sound right?

> 
> Thanks again.
> 
> Davin Ellicson
>