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Hi Marti,
Firstly, thanks for putting up with all my talk
about the i1 profiles on this list. ;^)
As I said, I think soft proofing is working ok in
Photoshop, using the i1 profiles. (no obvious problems)
I've just tried it using absolute intent, and the
appearance on screen, when using a D65 i1 monitor
profile,
looks similar to when I use sRGB for my monitor profile. (I have not inspected it very carefully
though)
What is *not* working is soft proofing *to* the i1
profiles, and then turning on gamut warning.
Soft proofing in Picture Window Pro 3.5 produces
*markedly* different results, however, when using the i1
profiles, to using traditional profiles, at least
when using the Microsoft/Windows CMM. I think the
reason
for the difference is that the Windows CMM does an
absolute intent conversion from the proof profile
to the monitor profile, and as we know, the i1
profiles don't work for absolute conversions if the monitor's
hardware whitepoint differs to D50.
Photoshop doesn't seem to do this. Photoshop seems
to do a relative conversion from the proof profile
to the monitor profile when "simulat paper white"
is disabled. When paper white is enabled, it adjusts
the appearance according to the mediawhitepoint tag
of the proof profile. If the media whitepoint tag
of the proof profile is higher in temperature
(bluer) than the illuminant (D50), the appearance becomes
bluer. If the media whitepoint tag of the proof
profile is lower in temperature (yellower) than D50,
the appearance becomes yellower. So, Photoshop's
simulate paper white assumes that the print
will be viewed with the same temperature light
source *as the monitor*. (this is my theory - waiting
for confirmation from the experts)
Greg.
----- Original Message -----
Sent: Wednesday, January 28, 2004 2:23
AM
Subject: Re: [Lcms-user] Re: Bug in Eye
One Match?!?!
Hi,
There is a way to check (perceptually) how well
performs monitor profile. You will need a printout of
any image with embedded profile. Obviously an
accurate print, I mean :-)
In the profiler, open the image and press the
triangle on upper left of the window. Then, in bottom, set the
combo box to "absolute colorimetric". If all is
ok, you will get a match-to-screen proof of printout
as viewed under D50 illuminant.
If the image was printed using right profiles, colors
inside monitor
gamut should look pretty same.
Regards,
Marti.
----- Original Message -----
Sent: Monday, January 26, 2004 1:33
AM
Subject: [Lcms-user] Re: Bug in Eye One
Match?!?!
I suspect that soft proofing to the i1 profiles
are also not working, even when using relative intent. I do this to see
whether
the image contains colours which are out of
gamut of my monitor, on occasion:
I did the following:
- Profile/calibrate monitor to D65 using
Eye One Display.
- Profile the monitor in the same calibration
state with the Little CMS
beta 3 monitor profiler, using the Eye One
Display puck.
- Open Photoshop 7.01, and create a blue patch (0,0,255)
and assign
ColorMatch RGB.
- View | Proof Setup | Custom, proofing
profile the i1 profile, intent
relative, blackpoint compensation off
-
View | Gamut warning (enable). Observe that image is out of gamut.
-
Image | Adjust | Hue Saturation, adjust saturation until gamut
warning
disappears. Adjust value required: -41%
- Cancel out of the hue/adjustment dialog (reset the image to
0,0.255)
Repeat these four steps, using the Little CMS profile:
Hue adjustment
required: -11%
Repat these steps using sRGB: Hue
adjustment required: -15%
I have trouble believing that the gamut
warning for the i1 profile
represents reality.
For the time being I really think I'm better
off just using the Little CMS profiler, at least until
I understand more about these i1 profiles.
Greg.
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