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  • Welcome to the new site. Here's a thread about the update where you can post your feedback, ask questions or spot those nasty bugs!

What's "practical" in color theory?

I'd like to jump out of the other thread in this section, in which the OP was getting a little long-winded, and Michael was getting a bit defensive in behalf of WhiBal, which is a great product, and meets specs that other products intended as white balance standards or not intended but still commonly used -- like the Pringles cap-- don't even publish, much less meet.

My definition of what is "practical" knowledge for color management, selection of camera profiles, creation of printer profiles, etc. is: If Norm Koren thinks it is worth measureing, I'll try to understand it. YDMV, but I find Norm's website at http://www.imatest.com a fount of useful information, clearly and concisely written. And I use his tool, Imatest, to see what raw development profiles are really doing, to test lenses and find their best operating conditions. His next product, gamutvision, which I haven't gotten experience with yet, promises to show you what a printer and RIP will and won't be able to do, before you sink your money in it. (practical?)

Have you invited Norm to be an editor or commentator in these forums? He will grumble about how busy he is, so ask him again.

My most recent discussion with him occurred when I showed L*a*b* plots from Imatest comparing the ColorEngine's profiles and RSP's default on the Pixmantec forum, in a sort of "here's the facts, whaddya think?" mode. I was hoping that Magnes would share some insight into how he sets up his profiles, but was not that lucky. However, he did say that the differences between the a* and b* values where the ColorChecker patches should be and where they turn up in the jpg's rgb values, when plotted in L*a*b* coordinates, are not the current best means of comparison. Norm's response, a week or two later, was to add CIE94 and CCM error measures to his scoring of color checker in Imatest. The issue is that the newer error measures give less weight to the differences at large saturation (bright, strong colors) where our perceptual sensitivity is also less. The Imatest site has several new pages of explanation of the different approaches, and gives formulae for those who, like me, find that a lot clearer than any number of words.

cheers,

scott
 

Michael Tapes

OPF Administrator/Moderator
Scott,

Thanks for the info, and yes, having Norm contribute or moderate would be great. I will suggest it to Asher. he is the diplomat. I am just a former NYer, and you know you can take the person out of NY but you cannot take NY out of the person. Although I am a lot more calm here in FL, and warmer!

I have asked Magne to contribute here, and he is sure to do so, with the frequency of his normal posting. Only when he comes down from his colorful mountain :>)
 

Diane Fields

New member
Michael Tapes said:
Scott,

Thanks for the info, and yes, having Norm contribute or moderate would be great. I will suggest it to Asher. he is the diplomat. I am just a former NYer, and you know you can take the person out of NY but you cannot take NY out of the person. Although I am a lot more calm here in FL, and warmer!

I have asked Magne to contribute here, and he is sure to do so, with the frequency of his normal posting. Only when he comes down from his colorful mountain :>)

Ah, both would be great to have here as well. This is a forum I followed often at the previous forum, so looking for some good discussion here.
 
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