[argyllcms] Re: Blue Cast to Color Munki Profile

  • From: Graeme Gill <graeme@xxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Thu, 28 Apr 2011 10:48:47 +1000

Alan Goldhammer wrote:
I think I figured it out by further reading on the website.  I prepared a
500 patch target but what was not clear to me were the settings in colprof
and what they should be set to.  I chose -i as D65 which is what my monitor
is calibrated to using NEC Spectraview software.  When I opened the Argyll

Hmm. No, it's not intended for that. It's where you tell it the actual
illuminant you will be viewing the print under. This has nothing whatever
to do with your monitor.

made profile in Photoshop and used it as the soft proof, there was a
noticeable blue cast to the image as though the bluish color from the OBA
was somehow showing up.  I remade the profile using all the defaults (D50

I guess Photoshop is using absolute intent for its soft proof, hence
this effect.

instead of D65) and only keeping -cmt&  -dpp respectively.  This profile had
no blue cast at all so I think the problem is solved.  What was curious is
that the blue cast did not show up in the print, only in Photoshop under
soft proofing.  With the blue cast in a profile, soft proofing to adjust
colors in Photoshop would be quite difficult.

If you are using any relative colorimetric rendering mode, then device white
is always rendered as device white, so no, you won't see any effect - or rather
the effect is more subtle than that. Specifying D65 as the viewing illuminant
will change the profile, since (depending on the spectral characteristics
of the inks) it will change the color of the patches. But the default
D50 and D65 have very similar spectral shapes, so the normal white point
adaptation will pretty much cancel any effect out using a relative intent.
The absolute white point difference will remain though.

I do have one further question that is not clear.  Suppose I settle on a
specified set of target patches to profile several different brands of
paper.  Is there any way in chartread to give the output *.ti3 file a unique
name different from the *.ti2 file?  I know that I can probably change the
file names in the directory but it would be easier to do it on the command
line.  I see in the online guide that you list under Usuage:  inoutfile as
"base name for input[.ti2]/output[.ti3] file.  Does this imply that I can
use a command such as  inoutfile: name1.ti2/name2.ti3 ?

No, you have to make a copy of the .ti2 file.

Graeme Gill.

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