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Colour within Photoshop

PostPosted: Thu Oct 12, 2006 6:16 pm
by Wocka
Gidday,

I have noticed a colour difference in Photoshop CS2 compared to ACDsee. After reading Chimp, I decided to try out DxO for RAW processing, normally I use RawShooter (actually I think I have seen this issue in RawShooter as well).

What happens is that I process a RAW file then open the 16Bit TIFF in PS and the colour look very different. So today I opened the TIFF in PS and though that looks very dull compared to what DxO previewed the final result to be. I then opened the image in ACDsee and had both images on the same screen (Dell laptop LCD) and the colours are quite different. In DxO and ACDsee it’s more vibrant and PS is just dull.

I have my camera set to Adobe 1998, Any idea’s what happening here?

Cheers,

PostPosted: Thu Oct 12, 2006 6:42 pm
by PiroStitch
could ACDSee and DxO be rendering the images in sRGB instead of aRGB?

Re: Colour within Photoshop

PostPosted: Thu Oct 12, 2006 7:07 pm
by DaveB
Wocka wrote:What happens is that I process a RAW file then open the 16Bit TIFF in PS and the colour look very different.

Ok, so at this point you have a TIFF file: the RAW conversion is done and the image should look the same in all software. So this has nothing to do with the way each software converts the colours in a RAW file.
What profile is attached to the TIFF file? The fact that your camera is set to AdobeRGB may have no impact, depending on the RAW converter. For example Photoshop's ACR will convert it to whatever colour space is selected at the bottom of the ACR window.

Whatever colour space the TIFF image was created in, it should have that profile embedded in it so that subsequent software knows how to deal with it.

Photoshop should honour the profile, but things can get confusing if you have the Color Settings set to unusual values. Have a look at the recommendations on this at the top of this page.

So today I opened the TIFF in PS and though that looks very dull compared to what DxO previewed the final result to be. I then opened the image in ACDsee and had both images on the same screen (Dell laptop LCD) and the colours are quite different. In DxO and ACDsee it’s more vibrant and PS is just dull.

Photoshop should be converting to your monitor profile properly, and I would assume (but don't know) that DxO should also be doing this. Similarly I don't know if ACDsee is using your monitor profile and the TIFF profile correctly.

I think we need some more detail, such as:
  • What profile is embedded in the TIFF file?
  • Is Photoshop set to honour that profile or is it assuming that the image is in Photoshop's default RGB space?
  • Incidentally, is your monitor profile set correctly?

Photoshop's colour handling is known to work correctly (if it's configured properly). I can't speak for the other software, maybe someone else can.

PostPosted: Fri Oct 13, 2006 11:55 am
by Wocka
Thanks for the reply Dave.

I have set PS up like the link shows and the colours are looking a lot better, I'd still say it lacks some contrast but it's 95% better. PS was set to Monitor RGB - Adobe (1998) I changed that to Adobe RGB (1998).

I couldn't find in my TIFF file where it has the colour profile set.

I looked at RawShooter and that is set for Adobe RGB (1998) when it creates the TIFF file, I can't see any option in DxO to set this. I'd expect it uses what the RAW filw was set to.

I doubt my monitor profile is correct since it's a Laptop and I have never calibrated it as I don't have a spider. But if both programs are on the same screen, shouldn't the colour be rendered the same as they are both using the same monitor profile.

Cheers

PostPosted: Fri Oct 13, 2006 12:23 pm
by DaveB
Wocka wrote:I have set PS up like the link shows and the colours are looking a lot better, I'd still say it lacks some contrast but it's 95% better. PS was set to Monitor RGB - Adobe (1998) I changed that to Adobe RGB (1998).

AdobeRGB 1998 is a good choice for the default colour space, but I'm concerned that what you've describe indicates that Windows has AdobeRGB set as your monitor profile, and that's not going to be correct!
Do you have the XP Color Control applet installed? If you're stuck using Windows (OK, so I'm a Mac user ;)) it's very useful so you know what's going on. You can download it from Microsoft's ProPhoto website (look for the Pro Photo Tools area).

I couldn't find in my TIFF file where it has the colour profile set.

Several ways. Try this: open the file in Photoshop, then call up Convert To Profile (or Assign Profile) and look in the subsequent dialog to see what the Source profile is. Then cancel the operation.

I doubt my monitor profile is correct since it's a Laptop and I have never calibrated it as I don't have a spider.

It definitely sounds incorrect. BTW, I do sell calibrators... :D

But if both programs are on the same screen, shouldn't the colour be rendered the same as they are both using the same monitor profile.

Yes they should be the same (as long as they're both using the profile!).