Ai6: CMS rendering to display on WinXP

[mct]

I am scanning transparencies on a Minolta Multi Pro. Using 48bit, and have both Ai and Photoshop set to PhotoPro RGB as working space.

Can you explain to me why I get different looking result in the scan preview windows, depending upon whether the CMS setting for Internal->Display is set for "CMS" or for "Auto"?

With Auto, it looks the same onscreen as it does in Photoshop's editing view, and looks "correct". (I have a calibrated monitor).

If I set to "Internal Colour Matching (ICM)", the preview obtained now does not look correct. The one in PS (after scan) is still the same as before, as I would expect.

So what transformations are occuring here? Exactly which profiles are being used (or not used), and why does it yield a different result? Is it possibly because Ai6 is just passing the internal working space data to Windows, which doesn't know how to transform PhotoPro RGB working space to monitor space?

Thanks...

[LSI_Noack]

Dear mct

the "auto" setting tries to access the Photoshop CMS settings and then uses these - quite successfully, as you're describing it.

The "ICM" (image color management) is a Windows system wide CMS which will need an .icm monitor profile activated for your Windows system to work properly.

Further reading on ICM by Microsoft:
http://msdn.microsoft.com/library/en-us ... t_5i91.asp

Best regards
Sonny Noack
- Manager Technical Support, LaserSoft Imaging AG -

[mct]

Hi Sonny,

I believe I do have an .icm monitor profile activated. If I check in Windows Display settings the profile is set as the default cms profile for the monitor.

If this weren't so, Photoshop wouldn't be able to find the monitor profile.

Can you elaborate a bit more on the interaction between Ai and Windows in this workflow configuration? (i.e. Standalone from PS). I think it should be possible to get the same result on the display regardless of whether the setting in question is set to ICM or Auto.

Cheers,
Milt

[LSI_Noack]

Dear Milt

I think it should be possible to get the same result on the display regardless of whether the setting in question is set to ICM or Auto.

As you describe how your system is setup, yes, both ways should get you the same result.
We would want to test this internally with your help.

Please don't hesitate to contact support: http://www.silverfast.com/problemreport/en.html
Thank you in anticipation of your kind co-operation.

Best regards
Sonny Noack
- Manager Technical Support, LaserSoft Imaging AG -

[mct]

I did some more controlled tests in my environment, and also found a useful forum post in another forum here.

In the end, I still do see a visible difference between the two scenarios, i.e. Ai doing the preview rendering through Windows ICM, and Ai asking Photoshop to do the rendering, which is what happens with the Auto setting.

The difference is very slight, and I put it down to some minor difference in the colour management engine that does the colour space conversion in Photoshop, vs the one that Ai or Windows is using.

I would be interested if anyone else has noticed this.

Rgds...