Re: [Leica] OT: Color calibration help needed

["John Evensta" <jevensta@plateautel.net>]

Nathan:

This is what is written in the link provided by Rolfe
(http://www.drycreekphoto.com/Learn/monitor_calibration.htm):

"You can see which monitor profile Photoshop (version 6 and above) is
actually using by opening Edit->Color Settings.  Expand the RGB working
space list, and scroll up.  You'll see a line with "Monitor RGB - xyz."  The
file listed instead of xyz is the monitor profile Photoshop displays all
images in.  This is important to check, as some profiling software packages
can write invalid profiles.  If this occurs, Photoshop ignores the profile
and displays in a default space that is guaranteed not to match your
monitor."

So if it says something like "Monitor RGB - Spyder," you will know that
Photoshop has automatically adopted your new monitor profile.

And this is something I found on ColorMatch RGB:

"ColorMatch RGB:
     Primarily if using images in D50 1.8 Gamma
     Much smaller and less perceptually uniform than AdobeRGB(1998)
     Can produce good imagery but AdobeRGB(1998) better"

If one's primary focus for color editing in Photoshop is web-based images,
this color space is certainly more than adequate.  But AdobeRGB(1998) would
probably be better when editing for a printed image.

And this is what it says in the VueScan help files (VueScan User's
Guide/Color tab):

"Note that if you use the Apple RGB, ColorMatch RGB, ProPhoto RGB or ECI RGB
color space, the image gamma will be 1.8. If you use any other color space,
the image gamma will be 2.2."

> > 3) Finally, in Vuescan I have let the program know that the monitor
> > color space is now the one I just created.
>
> Hmmm. You don't want to be editing in the monitor color space, if that
> is what you mean here.

You were right in telling VueScan to use the new monitor (*.icm) profile,
although this only affects the "Preview" or "Scan" images shown in the
VueScan program itself (Photoshop should have automatically adopted the new
monitor profile).

John Evensta



- ----- Original Message -----
From: "Rolfe Tessem" <rolfe@ldp.com>
To: <leica-users@mejac.palo-alto.ca.us>
Sent: Sunday, September 21, 2003 2:41 PM
Subject: Re: [Leica] OT: Color calibration help needed


> Nathan Wajsman wrote:
>
> > Some of you may recall the color disaster and the ensuing discussion a
> > few weeks ago after I posted a picture of my daughter on a rollercoaster
> > which looked fine on my PC but awful on most other people's. Following
> > the advice I received, I have bought the Optical Spyder calibration
> > device from Pantone and have now calibrated my monitor with it. The
> > resulting ICM profile is now the default profile on my monitor. So far
> > so good. The only difference I can see is that the screen looks a bit
> > more pink than before. Now to my questions:
> >
> > 1) I know that Windows gamma is supposed to be 2.2 but I use Colormatch
> > RGB as my working space in Photoshop, and so following the advice in the
> > Spyder manual I selected gamma=1.8 and color temperature=5000K when
> > doing the calibration. Is this going to create an issue when I post my
> > images?
>
> Yes, you should have set gamma to 2.2 even though it is a Mac. The 1.8
> recommendation dates back to old Apple monitors for which that was the
> native gamma. Color temperature of 5000K often looks too red, but this
> is a somewhat subjective judgement and depends on the monitor and the
> ambient room lighting. I've found that 6500K in a dimly lit room works
> best for me.
>
> There is lots of good material on this and other color management issues
> here:
>
> http://www.drycreekphoto.com
>
> > 2) There is no obvious place in Photoshop where I can let the program
> > know that the monitor color space is now the one I just created. But I
> > assume that since I let Optical set the new space as the default, all is
> > well. Am I right?
>
> Not sure about your question here, but you should be editing in a
> wide-gamut color space, most commonly Adobe RGB. I'm not familiar with
> Colormatch RGB. Under OSX, once you've selected the correct display
> profile in the Displays Color tab in System Preferences, every
> application including Photoshop knows about it.
>
> > 3) Finally, in Vuescan I have let the program know that the monitor
> > color space is now the one I just created.
>
> Hmmm. You don't want to be editing in the monitor color space, if that
> is what you mean here.
>
> >
> > With the above, am I right in assuming that now, if an image looks good
> > to me, it will look good to everyone else (or at least most people),
> > composition and content aside? Or is there more to this color thing than
> > I realize?
>
> As the saying goes, it's not brain surgery but getting all the details
> right can be annoying to say the least. It took me a good year to get
> the wrinkles out, so don't feel bad :-). I can now send a file to a
> digital printer, be it a Frontier or a Lightjet whatever, with
> confidence that I'll be getting what I thought I would be getting. The
> web, of course, is a long way from being fully color managed end-to-end
> so you may get unexpected results here from time to time.
>
> >
> > Thanks in advance for your indulgence. If this does not work out, I will
> > definitely give up on posting color images and stick to B&W...
> >
> > Nathan
>
> --
> Rolfe Tessem      |     Lucky Duck Productions, Inc.
> rolfe@ldp.com     |     96 Morton Street
> (212) 463-0029    |     New York, Ny 10014
>
> --
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