Adobe RGB (1998) profile problem *

[Sinisa]

Hi all!

I've come across a problem with some files with embedded Adobe RGB (1998) profile that have an * in the document profile name next to the bit size - for example IMAGE03.tif @ 100% (RGB/8*).

My working space is Adobe RGB (1998) but this seems to be a different Adobe RGB (1998) even though it has exactly the same name. I know this because when I assign Adobe RGB (1998) profile (in Edit/Assign profile) to a file with Adobe RGB (1998) with an * the colours change a lot, as if I'm assigning a profile with a very different gamut.


I'm assuming this has something to do with the source these images are coming from... but I can't get my head around this! More importantly, I don't know if I should leave these files with their own Adobe RGB (1998)* or convert them to my working Adobe RGB (1998).


Cheers,

Sinisa

[pixelzombie]

does this show up only in photoshop?...do you see the same issues in lightroom or aperaure?

[Sinisa]

I don't use Lightroom... I guess it comes up once the document is open in Photoshop.

[pixelzombie]

you could try opening each profile to see if there are any actual differences between the 2...

[Sinisa]

or to put it this way:

some files, even though they have embedded Adobe RGB (1998) colour profile, CHANGE a lot in terms of tone & colour when I convert them to my Adobe RGB (1998) colour space. I don't get this....

[TommyO]

Sinisa,
At first I was concerned that one of your ICC profiles could be corrupt. But after thinking about it, I don't think so. And, I don't see why you should worry about the embedded profile either. It could be a valid profile, but likely is not.

It sounds like someone else was working under an altered color space and hence color corrected the files improperly. That's why when you do convert them their colors look off.

I would just convert them to a valid color space (i.e. your AdobeRGB 1998) and then color correct them again.

As you pointed out, the "*" at the end of the "Adobe RGB" string in the title bar means that the embedded profile does not match your working color space. In this case they're both named the same, but Photoshop knows they are not the same. I cannot recall what Adobe uses as the criteria for comparison in such a case. But, it obviously isn't just the name.

I hope this helps answer your question, but if not, just ask again.

[ReneDamkot]

Yep, the asterisk meant that the embedded profile is not the same as the working space :
http://img.skitch.com/20090705-gewsf...s2nnn16a1u.jpg

Originally Posted by Sinisa

or to put it this way:

some files, even though they have embedded Adobe RGB (1998) colour profile, CHANGE a lot in terms of tone & colour when I convert them to my Adobe RGB (1998) colour space. I don't get this....

Now you're talking about converting. In the first post you said you were assigning. Which is it?

When converting, depending on rendering intent used (in this case Relative Colorimetric), colors that are in the destination spaces Gamut, should not change at all.

[Flashtones]

I feel like I read something about this once but forgot it before fully digesting it, but it might have something to do with how the digital camera is set to tag (profile) files.

Are these images your own, from your own camera? If so, read up on the camera settings to review your options, and perhaps ask your question on a camera brand specific message board (ie, Canon or Nikon, etc).

If, in PS, you like how the images look with their current profile you can probably just leave them as is, or "convert" them to AdobeRGB, which should maintain the current look. If you prefer the way they look after "assigning" AdobeRGB to them then do that (assign it), and then convert them to AdobeRGB. That will maintain the look of the assigned profile.