Datacolor User to User Support Group.

Thanks CDTobie and David Miller for the extensive replies.

So to summarise I guess I should not worry too much about the out of
gamut warnings ? Would you recommend I take some action if I see this
out of gamut warning or should I just let Photoshop and the Printer
Driver figure out the best thing to do with these colours ?

Thanks again ! I think I am slowly 'getting it' :-)

Rgds
Rick

--- In colorvision_group@yahoogroups.com, David Miller <dm2363@...> wrote:
>
> 
> On Sep 10, 2008, at 6:08 AM, rickbehl wrote:
> 
> > Hi,
> >
> > Please could someone help to answer a question.
> >
> > My setup is:
> >
> > Screen: Dell LCD 1703FP
> > OS: Windows XP
> > Screen Calibration: Spyder3 Elite - 2.2/6500k
> > Printer: Epson 3800
> > Printer Profiling Device: Spyder3 Print
> > Paper: Epson Archival Matte Paper
> > Inkset: Epson Ultrachrome (standard with this printer)
> >
> > I have built a printer profile for this printer/paper/ink combination.
> > In fact I built 3 profiles:
> >
> > 1) From the Expert + Grays target (4 sheets altogether) - Take
> > measurements after 1 day drying time
> > 2) From the Expert + Grays target (4 sheets altogether) - Take
> > measurements after 2 days drying time
> > 3) Average the two profiles above
> >
> > On all 3 profiles when I soft proof the image in Photoshop CS3 there
> > are a lot of areas showing as gray (Out of Gamut) which do not appear
> > as such when I soft proof using the Epson canned profile (Pro38 ARMP).
> >
> > Noticeably these are in the darker areas: Dark blues, greens,
> > blacks/greys, purples, browns. The colours which seem ok (in Gamut)
> > are yellows, cyans and generally the lighter shades.
> >
> > If I print a test image (Using the Photodisc colour test image) using
> > the profiles, the colours are definitely better with the Spyder3
> > profiles but I am concerned about why there are so many grey/Gamut
> > warning areas on the soft-proof...
> >
> > Please could someone advise ?
> >
> >
> 
> The real issue here is this: the out-of-gamut warning you're getting
> with our profile is actually, -technically correct-. Here's why:
> 
> You're profiling matte paper. The L values (lightness) for all of the
> shadows on matte paper measure lighter than on glossy/luster. On matte
> paper, measured L for black will be in the 15-22 range, usually in the
> upper teens. On glossy/luster, measured L for black will be in the 3-7
> range (but usually not more than 5).
> 
> The out-of-gamut warning is telling you that shadow values, with their
> darker L's, fall below the measured values for the printer gamut.
> (And, in fact: they do!) If you were doing this with a profile built
> from glossy/luster with much darker blacks, the gamut warning
> would cover a much shallower area of the darkest shadows.
> 
> There's nothing "wrong" with this. On matte paper, you simply cannot
> prints black, and shadows, that cover the same range as glossy/luster
> papers. The gamut warning is telling you this, and there is nothing
> you can do... because it's physically impossible for you to print
> darker on that printer, on matte paper.
> 
> The fact that you're getting gamut warnings in the shadows doesn't
> mean that there will be a problem with the print. You will be getting
> the darkest blacks and shadows that the printer/paper/inkset can
> give you, when you print; the gamut warning is just doing what
> it's supposed to do: tell you that you're trying to print darker
> blacks and shadows than the printer/paper/inkset can physically
> produce.
> 
> So: why don't you get a similar gamut warning with Epson profiles...?
> 
> You should, but the Epson profiles are doing something different
> with an internal table in the profiles (which has to do with how
> the gamut warning is calculated) to "hide" the fact that these
> shadows are actually outside the printer gamut for matte papers.
> The gamut shape in the Epson profiles isn't any larger than
> in a profile we've created for the same paper; in fact, our gamut
> shape is likely to be a bit larger. If you use a utility like
> Chromix ColorThink to compare the gamut shapes for a Spyder3Print
> profile on Epson Enhanced Matte, vs. the Epson profile for the same
> paper, you'll see that the gamut shapes are similar and that the
> bottom tails both "float" above the L = 0 plane at pretty much the
> same level.
> 
> ***
> 
> The shorter answer is: don't worry about this. We're actually
> giving you a more accurate gamut warning than the Epson profiles;
> the fact that those shadows are technically out of gamut doesn't
> mean that there's anything wrong with the print. Your direct experience
> is that the print is great... and in fact, better than what you
> get from the Epson profiles.
> 
> 
> David Miller
> Senior Software Developer, Digital Color Solutions
> Datacolor
>