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1. Re: Color Settings (Profile) Question
Curt Y Jun 4, 2010 8:50 AM (in response to rollsnut)Yes you should be able to just change as you stated. ProPhotoRGB is a wider gaumet color range so some color shifting may be evident. This gets into a very complex subject, or which I am not an expert.
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2. Re: Color Settings (Profile) Question
D Fosse-QDEaQ1 Jun 4, 2010 9:14 AM (in response to rollsnut)In short: use convert, not assign.
Convert changes the RGB numbers to keep the appearance unchanged.
Assign keeps the numbers, but the interpretation of the numbers is different, so the colors change.
Expect some color channel clipping when you go from ProPhoto to sRGB. Yes, in a sense ProPhoto is better, because it's bigger and contains more colors. But you have to know the implications of that to take advantage of it. It mainly gives you a lot more headroom in the editing stage. The trick is to squeeze it back into sRGB or Adobe RGB for final output.
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3. Re: Color Settings (Profile) Question
rollsnut Jun 4, 2010 10:52 AM (in response to D Fosse-QDEaQ1)Ok, I think I have the solution and I'll post it here in case anyone else has the same
problem in the future.
My buddy called ( he feel really bad for messing me up in the first place) and he offered this solution which works and makes sense....
Open the photo
EDIT
ASSIGN PROFILE - to make sure it has the ProPhoto profile.
CANCEL
IMAGE
MODE
Select LAB COLOR
IMAGE
MODE
Select RGB
To verify change:
EDIT
ASSIGN PROFILE - find that sRGB radio button is selected.
Now just to create a macro(Action) to mass process them all!
Thanks to all who read this and offered solutions.
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4. Re: Color Settings (Profile) Question
D Fosse-QDEaQ1 Jun 4, 2010 11:16 AM (in response to rollsnut)Just convert to (not assign) sRGB and be done with it.
There's no reason to go via Lab.
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5. Re: Color Settings (Profile) Question
rollsnut Jun 4, 2010 11:32 AM (in response to D Fosse-QDEaQ1)I believe you and for some reason it worked on some of the files but
not all of them - I don't know why. The process I did was full proof on
ALL the files.
You are probably 100% correct in most cases and I did use your method until it failed on several files and I had to find a way to conver them.
Thanks for your input. I'mnot slighting it in the least.
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6. Re: Color Settings (Profile) Question
Noel Carboni Jun 4, 2010 11:41 AM (in response to D Fosse-QDEaQ1)function(){return A.apply(null,[this].concat($A(arguments)))}
D Fosse wrote:
In short: use convert, not assign.Convert changes the RGB numbers to keep the appearance unchanged.
Assign keeps the numbers, but the interpretation of the numbers is different, so the colors change.
Expect some color channel clipping when you go from ProPhoto to sRGB.
I have developed an action that affects this exact conversion (ProPhoto RGB to sRGB) without clipping (but with color shifts instead to compensate for out-of-gamut colors). In a sense, less data is lost through the use of this action.In fact, it's a good idea, if such clipping bothers you, to always convert raw files into ProPhoto RGB then use a "less lossy" technique like this action to convert to sRGB, because the channel clipping mentioned by D Fosse above happens during conversion as well.
If you'd like to try the action:
Run it on a flat ProPhoto RGB image and you'll get a flat sRGB image. Simply put, it shifts some colors to fit the smaller color space, while attempting overall to maintain the original color. It works around the clipping of color channel data one sees from Absolute Colorimetric conversions directly to sRGB..
http://noel.ProDigitalSoftware.com/temp/ColorSpaceAction.zip
Right click the above, unzip, and save the .atn to your disk.
Load into Photoshop via the Actiona Palette menu, Load Actions entry.
Open a raw image into ProPhoto RGB (I recommend 16 bit), then run this action at some point after to convert the image to sRGB. I have assigned it to a function key.
Enjoy!
-Noel
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7. Re: Color Settings (Profile) Question
D Fosse-QDEaQ1 Jun 4, 2010 4:21 PM (in response to rollsnut)rollsnut wrote:
it worked on some of the files but not all of them
The thing is, if you start assigning profiles you get into deep waters pretty quickly. The file itself is unchanged; the RGB values the same - but the colors change completely because the numbers suddenly have a different meaning.
So that's when you need to retrace your steps to get back to where you were. Then you need to reassign the original profile.
But apart from that, convert is what you want.
As for Noels action I've tried it and it works. The term for what it does is gamut mapping - or rather remapping (personally I prefer to do that manually, but that's a different story).
Here's an example of a strong yellow-green that causes blue channel clipping in sRGB:




