Photoshop CS2 colour problem (warning: big pics)

[cybertect]

FWIW, my workflow starts with Adobe Camera RAW and I convert directly to sRGB, which is my working colour space in Photoshop. Since most of my photos are targeted for the web or printing via drivers that work in sRGB, I'm prepared to put up with the smaller colour space compared with Adobe RGB. Final files for the web are saved with an sRGB tag.

I'm wondering slightly about your mention of assigning, not converting colour spaces earlier in the thread. AFAIK, assignment just maps to the target colour space without any reference to the source space and should only really be used when dealing with untagged files, or if the tagged version is unsatisfactory and you're (randomly) fishing around for something better. Assign a colour profile to a previously tagged file and you'll probably get unexpected results.

When working with sRGB files, I'd expect non-colour managed applications on Windows to use that as their default colour space, so you should see little or no difference between an untagged and sRGB tagged file in those.

It might also be worth reading Microsoft's notes on the subject under XP

http://www.microsoft.com/windowsxp/using/digitalphotography/prophoto/colorspaces.mspx

 

[mauvais]

You're right about how assigning/converting works. The trouble is that the non-managed image is wrong, and the managed image is right. Therefore there are two options:

(a) drop the colour management by discarding the profile

or

(b) shift the problem along one step by assignment then conversion; that way, the managed image is wrong but the non-managed one is right. Do you see why this works?

Anyway, there's no big difference between assigning my monitor profile and the Adobe 1998 profile, but still trouble with sRGB, as far as I can tell.

E2A: there is a big visible difference between sRGB unprofiled, and profiled, in Windows, and this change is visible when you unassign the profile in Photoshop.

 

[cybertect]

I'm used to Macs and ColorSync, so I'm a little lost with Windows colour management (is that a non-sequitur or a contradiction of terms? )

Just so I'm clear, are you normally assigning your calibrated monitor profile to the image in ACR before it hands it off to Photoshop?

 

[mauvais]

No - you can't do that. In ACR itself, I use whatever I took the original pictures in - at the moment, Adobe 1998.

Then comes the clash, as the Photoshop working space is of course my monitor profile. I normally choose to convert to the working space.

 

[cybertect]

Ah. That's where I'd reckon your problem is.

You should aim to minimise the number of conversions of colour space as you're inevitably going to encounter clipping as you translate from one space to another (different spaces have different gamuts, so a green that's obtainable in one space may be clipped back in another, for example).

By converting to your Monitor's calibrated space directly after conversion to Adobe RGB, you're practically guaranteeing that some colour clipping will occur. If you do a further conversion to sRGB for the web at a later point, you're likely to clip further boundaries from the space available for your image. Hand your image on to someone else and, unless you also send them a copy of your monitor profile, they're definitely going to see the colours differently than you do, which rather defeats the object of standard colour spaces like Adobe RGB or sRGB.

I'd thoroughly recommend against using your monitor profile as the working space. PS should deal with the colour on the fly without needing it to be explicitly referenced in your Colour settings. That's why the calibrated profile appears with 'Monitor RGB' affixed to the start of its name - it already knows what that is.

I'd stick with Adobe RGB as the working space and convert only at the last possible minute to another space, such as sRGB for web use, or use sRGB all the way through if you're unlikely to be sending jobs to professional presses. You don't have to use Adobe RGB just because that's what you have set on your camera if you're processing RAW files with ACR, as that effectively defers your choice of colour space until the moment you click 'Open' in ACR, much as you do with your exposure choices. The colour space settings on the camera are intended for use when you're shooting in JPEG. You can effectively ignore it with RAW processing.

 

[mauvais]

That's a pretty useful post - cheers. I'd forgotten that the camera colour space only affected the JPEGs, as the default ACR option changes with it, and misled me a little.

I'll give it a go without using the monitor profile as the workspace. However I suppose now that the monitor profile essentially equals Adobe anyway, but not sRGB, my problem has become this - sRGB is shit!

Oh well

 

[Sasaferrato]

They do look different to me.

The one underneath has more of an orange coloured tint to the postbox.

Yes, it does.