Datacolor User to User Support Group.

--- In colorvision_group@yahoogroups.com, CDTobie@... wrote:
>
> 
> In a message dated 1/20/08 11:36:06 AM, jeanchristophe.marie@... 
> writes:
> 
> 
> > Thank you for your answers. I will try with white and black
> > compensation newt week-end (not at home this week). It is matte
paper...
> > 
> > I don't have photoshop but Qimage. The chart is printed with Qimage
> > then measured with PrintFix Pro (I wil update, Ididn't know that I
> > could upgrade. Thanks colorvision!).
> > When I say that white becomes blue on soft proof, it is in Qimage.
> > Turning on black compensation in Qimage doesn't change anything. I've
> > never soft proofed in PFP.
> > 
> Whites turning blue indicate that you are using an artificially
whitened 
> paper. Checking the checkbox in Ref White should solve that.
Checking the checkbox 
> in Ref Black should reduce your "grayveil" effect as well,
especially on 
> matte papers.

I'll try next week-end.

> > 
> > What I don't understand with the blue cast:
> > - when I calibrate the spectrocolorimeter with the paper, all the
> > patch are as I see them on the paper. That is, I think, a ggod
thing...
> > 
> No, that is a major error, and will cause inaccuraccy. Never
calibrate on the 
> paper, only on the white tile...

I did it because of the blue cast. Ref white did a yellow soft proof.

> 
> > - when I calibrate it on the calibration base, all white colors are
> > blue. This is quite different from what I see on the paper! And I
> > should see on the screen what is on the paper during the measurement.
> > 
> If the whitepatch (paperwhite) of your target measurements (after
calibrating 
> on the white tile!) is showing up as a bright Cyan, instead of
white, that is 
> hardware issue, and you will need to contact support at
ColorVision.com to 
> get your spectro replaced. But first, clean the whitetile with
rubbing alcohol 
> and a paper towel (don't use cloth, it may have whiteners in it).
See if white 
> then measures as white; if its still bright Cyan, then contact
support for a 
> replacement.

Not a good news... When the spectrocolorimeter is calbrated on the
hard white support (the good method), it gives 0.1 density and gray
color. Then, when I measure the white patch of the printed chart or a
new white paper (Hahnemuhle Natural Art Duo), the measured color is
bright cyan. The right patches of the extended gray chart are bright
cyan too.
Whites on soft proof are blue if ref white unchecked. Whole soft proof
is yellow if ref white is checked.
I cleaned it with cotton without alcohol. I'll try with alcohol next
week-end.

Thanks for all.

> 
> C. David Tobie
> Product Technology Manager
> Digital Imaging & Home Theater
> Datacolor Inc.
> CDTobie@...
> www.datacolor.com/spyder3
> 
> 
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