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hkulokari
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Lightroom 3.6 and DNG Profile Editor

Dec 13, 2011 1:11 PM

After updating to LR 3.6, DNG Profile Editor does not display previews correctly, if base profile is one of the "new technology" camera specific profiles (for example the v4 profiles for Nikon). It looks like the previews are not properly converted to sRGB for display.

 

I also noticed that if I decompile and then compile such a profile using dcptool of Chromasoft, the resulting profile generates very strange looking pictures.

 

 

- Hannu

 
Replies
  • Currently Being Moderated
    Dec 13, 2011 9:49 PM   in reply to hkulokari

    As regards dcpTool, can you give me some more details - exactly what profile you were converting, and what the command lines you were using to decompile and compile again?

     

    Sandy

     
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    Dec 14, 2011 2:28 AM   in reply to hkulokari

    Those command lines should give an identical profile, and so far as I am aware, Adobe haven't changed the DNG spec. Or at least, if they have they're keeping very quiet about it(!)

     

    It may possibly be a bug in dcpTool - I'll do some checking and see - give me a few days.

     

    Sandy

     
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    Dec 14, 2011 6:33 AM   in reply to sandy_mc

    There are some new tags being used by the v4 profiles.  We are working on a corresponding spec and SDK update.

     
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    Dec 14, 2011 6:46 AM   in reply to hkulokari

    As I have written above, there are some new tags in the v4 profiles, and we are working on a spec and SDK update.

     
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    Dec 14, 2011 6:48 AM   in reply to hkulokari

    Yes, well, there are indeed new tags. Notably the following, from exiftool:

     

    Exif 0xc7a4                     : 1

    Exif 0xc7a5                     : -0.5

    Exif 0xc7a6                     : 1

     

    I'd guess these are offsets to the curves, or something similar, to get round posterization issues. That's consistent with what a V4 profile stripped of the new tags does, which is basically to overexpose.

     

    However, the bad news is, until Adobe publish a new version of the SDK and documentation, dcpTool will remain broken for V4 profiles. I'll try to do an update of dcpTool once the new SDK is out. Well, soon after anyway - getting the SDK and the XMP toolkit to compile is always a nightmare.

     

    Sandy

     
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    Dec 14, 2011 11:07 AM   in reply to sandy_mc

    Thanks team for the info.

     
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