ICC color profile problem when converting from camera RAW to DNG format

[Robert]

Hi all,

I'm new to Photo Mechanic (Mac OS X, version 4.5.2) and Adobe Camera Raw 4.1.
I've taken Canon EOS 5D raw files with the setting on the camera that the images are taken in the Adobe1998 color model.  I then download these raw-files (CR2) to disk and open them in PhotoMechanic. All relevant camera metadata including the correct ICC profile (Adome1998) pops up under the 'Camera Info' window-tab.
I use Adobe Camera Raw 4.1 (part of CS3) to correct the raw files followed by a conversion to DNG-files. So far so good. However, when I open the DNG-files in Photo Mechanic and look at the camera info I can only see part of the metadata which I see in the raw-file. Fields are blank and the ICC profile is sRGB instead of Adobe1998.
I then loaded the same DNG-files in Photoshop CS3. Looking at the "File Info" in Photoshop the color model appears to be Adobe 1998 which is correct. My settings in Photoshop CS3 are a default color model of Adobe1998 and a warning when an image is loaded with a different color model. This warning doesn't show up thus the colo model apparently is Adobe1998.

Why do I see a different color model in Photo Mechanic? Am I doing something wrong or do i misunderstand someting?

Thank you in advance for your help.

Robert Kroon
 

[Kirk Baker]

Robert,

I'm new to Photo Mechanic (Mac OS X, version 4.5.2) and Adobe Camera Raw 4.1.
I've taken Canon EOS 5D raw files with the setting on the camera that the images are taken in the Adobe1998 color model.  I then download these raw-files (CR2) to disk and open them in PhotoMechanic. All relevant camera metadata including the correct ICC profile (Adome1998) pops up under the 'Camera Info' window-tab.
I use Adobe Camera Raw 4.1 (part of CS3) to correct the raw files followed by a conversion to DNG-files. So far so good. However, when I open the DNG-files in Photo Mechanic and look at the camera info I can only see part of the metadata which I see in the raw-file. Fields are blank and the ICC profile is sRGB instead of Adobe1998.
I then loaded the same DNG-files in Photoshop CS3. Looking at the "File Info" in Photoshop the color model appears to be Adobe 1998 which is correct. My settings in Photoshop CS3 are a default color model of Adobe1998 and a warning when an image is loaded with a different color model. This warning doesn't show up thus the colo model apparently is Adobe1998.

Why do I see a different color model in Photo Mechanic? Am I doing something wrong or do i misunderstand someting?

I don't know why there would be a difference, but if you're willing to send us a sample image that exhibits the problem we'll look into the issue.

Contact me directly by clicking on my name to the left of this message and send me a Personal message.  I'll respond with server upload information.

-Kirk

[msbc]

Hi Kirk,

Did you ever manage to identify/resolve this problem? I just found I'm having the same issues. Using PM 4.5.3.2 and DNG Converter 4.6. I convert a Canon 5D CR2 to DNG and compare values in the Info display of PM. I see the following differences:
CR2
Date: 5:21:14 PM, 5/10/08
Model: Canon EOS 5D
Frame #: 1126
Focal Length: 70mm (70mm)
Lens:  EF70-200mm f/4L USM
Exposure: 1/200s @ f13 - ISO 100
Exp. Comp.: 0.0
Flash Comp.:
Program: Manual
Focus Mode: AI Focus AF
White Bal.: Auto
ICC Profile: Adobe RGB (1998)

DNG
Date: 5:21:14 PM, 5/10/08
Model: Canon EOS 5D
Frame #: 3
Focal Length: 70mm (70mm)
Lens: 
Exposure: 1/200s @ f13 - ISO 100
Exp. Comp.: 0.0
Flash Comp.:
Program: Manual
Focus Mode:
White Bal.:
ICC Profile: sRGB Profile

You notice some values are blank (Lens, Focus Mode and White Bal.) and specifically the ICC Profile has changed to sRGB from ARGB.

If I run exiftool over the DNG it tells me the 'Color Space' is ARGB.

[Kirk Baker]

Did you ever manage to identify/resolve this problem?

I don't believe we ever got a sample image.  If you're willing to send us one (both the original CR2 and the DNG, please) then click on my name to the left of this message, then click on the 'personal message' link.  I will respond with upload instructions.

-Kirk

[kwell]

One possible source of confusion is that camera raw images do not have a color space at all. Your camera still generates an embedded JPEG preview, and will do it in the color space you specified in your camera menus.

When you convert to DNG format, the embedded JPEG preview is always in sRGB color space. However, the metadata tag may still persist with the camera's color space setting for JPEGs.

This won't cause you trouble if you're actually opening the DNG via a program that can decode the DNG file (rather than using the embedded JPEG preview). In fact, you can tell it to open the DNG file into any color space you wish. If you are using the built-in JPEG preview of the DNG file, forcing the application to read it as if it were in a color space other than sRGB will lead to problems.

Here's a thread on the matter from Peter Krogh's site, in case it helps.

-Kevin