Archived posting to the Leica Users Group, 2003/09/21

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Subject: Re: [Leica] OT: Color calibration help needed
From: Rolfe Tessem <rolfe@ldp.com>
Date: Sun, 21 Sep 2003 16:41:39 -0400
References: <3F6D6BC0.D332D577@chello.nl>

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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Replies: Reply from "John Evensta" <jevensta@plateautel.net> (Re: [Leica] OT: Color calibration help needed)
In reply to: Message from Nathan Wajsman <n.wajsman@chello.nl> ([Leica] OT: Color calibration help needed)