Datacolor User to User Support Group.

Hi,

Thanks for your help earlier today. I worked out the file naming problem but noticed a 
peculiar thing when I soft proofed one of the grayscale images provided by DataColor. The 
profile that I used was made from the expert target plus the extended grayscale target. When 
I clicked the on screen soft-proofing on and off I noticed that the image actually warmed up 
with a slight sepia tint when the soft proof box was checked.

Why is that? I expected to see a change in tonal range, but not a small color shift. Upon 
output, it does appear that the image might have a slight sepia tint to it, but I did not add 
that tint when I originally built the profile. Any ideas what's going on?

John

Print the lower right test image, and measure the large medium gray  
patch using the tool menu's measure command. See what the a* and b*  
values are. They should be neutral, even if your output has a  
metameric cast under your viewing light.

C. D. Tobie
WW Product Technology Mngr.
Digital Imaging & Home Theater
DataColor.com
CDTobie@...

On Jan 4, 2009, at 7:54 PM, "John Arnold" <john.arnold@...>  
wrote:

> Hi,
>
> Thanks for your help earlier today. I worked out the file naming  
> problem but noticed a
> peculiar thing when I soft proofed one of the grayscale images  
> provided by DataColor. The
> profile that I used was made from the expert target plus the  
> extended grayscale target. When
> I clicked the on screen soft-proofing on and off I noticed that the  
> image actually warmed up
> with a slight sepia tint when the soft proof box was checked.
>
> Why is that? I expected to see a change in tonal range, but not a  
> small color shift. Upon
> output, it does appear that the image might have a slight sepia tint  
> to it, but I did not add
> that tint when I originally built the profile. Any ideas what's  
> going on?
>
> John
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

The gray patch measures L=46.81, a=(+0.65) , b=(-0.64). Is that about right? Maybe it's 
just the incandescent lighting that I am using to view the print. One thing I still don't 
understand is why the soft proof window preview seems to get warmer when I check the 
soft proof box to "on". Why would it take a grayscale image and make it look warmer on 
screen? 

John


--- In colorvision_group@yahoogroups.com, Cdtobie <CDTobie@...> wrote:

>
> Print the lower right test image, and measure the large medium gray  
> patch using the tool menu's measure command. See what the a* and b*  
> values are. They should be neutral, even if your output has a  
> metameric cast under your viewing light.
> 
> C. D. Tobie
> WW Product Technology Mngr.
> Digital Imaging & Home Theater
> DataColor.com
> CDTobie@...


>

--- 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

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
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

--- 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.
> 

Can you preview the soft proof before you commit the White Reference 
edits or do you have to keep rebuilding the profile until you get it 
right?

You have to rebuild, softproof, and rebuild again. Since this takes  
only a few seconds per iteration, it's not too bad.

C. D. Tobie
WW Product Technology Mngr.
Digital Imaging & Home Theater
DataColor.com
CDTobie@...

On Jan 5, 2009, at 7:20 PM, "John Arnold" <john.arnold@...>  
wrote:

> --- 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.
>>
>
> Can you preview the soft proof before you commit the White Reference
> edits or do you have to keep rebuilding the profile until you get it
> right?
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

--- 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

Two possible factors here. First, and I hate to bring this up;  
Photoshop's paper white emulation tends to accentuate any  
nonneutrality in papertone to an unreasonable degree. Please note that  
the softproof in Spyder3Elite is actually better about this.

Second, there is indeed a tendancy to use a moderate amount of  
whitener is lots of papers; about a negative unit and a half in b star  
value is typical. Some papers, especially photocopy/laser papers, may  
go way, way over the top when attempting to brighten a dull pulp  
colored paper. Unless you are using a media that specifies unwhitened  
or natural, this is to be expected. A measured neutrality is not  
really what papermakers strive for, they want a subjective impression  
of "pure as the driven snow" which requires a measurable amount of  
brighteners to achieve.

C. D. Tobie
WW Product Technology Mngr.
Digital Imaging & Home Theater
DataColor.com
CDTobie@...

On Jan 11, 2009, at 2:08 PM, "John Arnold" <john.arnold@...>  
wrote:

> --- 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
>
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>

--- In colorvision_group@yahoogroups.com, Cdtobie <CDTobie@...> wrote:
>
> Two possible factors here. First, and I hate to bring this up;  
> Photoshop's paper white emulation tends to accentuate any  
> nonneutrality in papertone to an unreasonable degree. Please note that  
> the softproof in Spyder3Elite is actually better about this.
> 
> Second, there is indeed a tendancy to use a moderate amount of  
> whitener is lots of papers; about a negative unit and a half in b star  
> value is typical. Some papers, especially photocopy/laser papers, may  
> go way, way over the top when attempting to brighten a dull pulp  
> colored paper. Unless you are using a media that specifies unwhitened  
> or natural, this is to be expected. A measured neutrality is not  
> really what papermakers strive for, they want a subjective impression  
> of "pure as the driven snow" which requires a measurable amount of  
> brighteners to achieve.
> 

Thanks. One thing that I still don't understand though is why when you calibrate the 
device on the white tile that the b* value is approximately negative 1.3 to 1.4. Is the tile 
intentionally trying to emulate paper whiteners? I have noticed that I am not the only one 
that gets readings in that range.

John