Datacolor User to User Support Group.

--- In colorvision_group@yahoogroups.com, Cdtobie <CDTobie@...> wrote:
>
> Your understanding of how to rebuild the profile with edits is  
> correct. But you would adjust the a/b values to the setting where they  
> gave you the softproof tone you desire, not simply to zero, though in  
> a perfect situation, that would do the trick for neutrality.
> 
> C. D. Tobie
> WW Product Technology Mngr.
> Digital Imaging & Home Theater
> DataColor.com
> CDTobie@...
> 
> On Jan 5, 2009, at 5:55 PM, "John Arnold" <john.arnold@...>  
> wrote:
> 
> > --- In colorvision_group@yahoogroups.com, cdtobie <CDTobie@>
> > wrote:
> >>
> >>
> >> ___
> >> Well, your paper tone is one reason, and your paper whiteners
> > could be another. Adjust the a*/b* values in the "Ref White" box and
> > rebuild your profile, to adjust the softproof tint.
> >> --
> >
> > Thanks. I have two questions regarding what you have recommended?
> >
> > 1) By adjusting my a*/b* values in the "Ref White" box do you mean
> > setting them both to zero?
> >
> > 2) In order to rebuild a profile, do I just choose the file where
> > the targets are saved that were originally used to build the profile
> > and then proceed to the next page where you build the profile? I
> > assume that's right as I don't know of any other way to call up an
> > existing profile to tweak it.
> >
> > Thanks,
> >
> > John
> >

Hi,

I have been thinking about this post and wanted to revisit. The paper I am using does in 
fact measure on the cyan side of white. a*/b* values are both slightly negative when I 
measure with the spectro and I only get the slight greenish cast when I check the 
"simulate paper white" box in Photoshop's proofing setup menu. So in reality, it appears to 
be correct. 

Thinking about this prompted me to ask why when I calibrate the spectro, that the b* 
value is always in the negative -1.32 range. I have noticed in the past that others who 
post to this site also frequently get negative b* values that are in the same range when 
they calibrate. I figure that's not accidental and maybe has something to do with 
compensating for paper whiteners or some such thing. I am curious as slight cast in the 
highlights are often more noticeable than cast elsewhere and I am trying to better 
understand how the product works so that I can correctly compensate for this type of 
thing when tweaking profiles. 

Hope the above makes sense.

Thanks,

John