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Replacing raw/dng masters?

Apr 2, 2012 12:28 PM

Tags: #raw #import #dng #file_size #lumix #rw2

I've been importing images using the 'Copy as DNG' option, and I have it set to use Camera Raw 4.6 and later (because I have Photoshop CS3, which I very occasionally want to use on the results).

 

I was surprised to discover today that my Lumix .RW2 files become enormous when I do this - they go from about 19MB to about 60MB. And I'm rapidly running out of disk space when travelling.  I don't have the 'embed original image' option set, so I think this is just a failing of early DNG formats.  If I use a newer version, I don't get the size expansion problem, but then I can't open it in my Photoshop, or Preview, or, well, anything much that isn't new and expensive from Adobe :-(

 

So I'd probably like to go back to just using my raw files, which rather more things can read, ironically, than the open DNG format!  Alternatively, I'll have to use a newer format of DNG and just forget about being able to open it elsewhere for the time being.

 

But for my existing images, is there a way I can replace my big DNG files with small RW2 files, or with newer versions of DNG files, and preserve the metadata, cropping, etc?

715 Views   6 Replies   Latest reply: -Agfaclack-, Apr 13, 2012 10:57 AM
 
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  • Dorin Nicolaescu-Musteață
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    1. Dorin Nicolaescu-Musteață,
    Apr 4, 2012 1:50 AM   in reply to quentinsf
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    What camera is that?

     

    Some cameras — notably 4/3 panas — include forced lens distortion correction. This only became possible in DNG v.1.3. I cannot recall now, but it's quite possible that ACR 4.6 does not support DNG1.3, thus the conversion creates a linear dng (i.e the image is demosaiced). That would explained a huge file size.

     

    What is you Lightroom version? If what I wrote above is the case, it doesn't quite make sence to you to choose such a low ACR version compatibility mode. If you need compatibility with Photoshop, you can always render files in Lightroom before handing over to PS.

     
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  • Dorin Nicolaescu-Musteață
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    2. Dorin Nicolaescu-Musteață,
    Apr 4, 2012 2:00 AM   in reply to quentinsf
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    But for my existing images, is there a way I can replace my big DNG files with small RW2 files, or with newer versions of DNG files, and preserve the metadata, cropping, etc?

    As for this, I guess you can use DNG converter to reconvert with a higher ACR version compatibility mode. You can also import your RW2 files along the big DNGs and sync metadata between DNG-RW2 pairs using John Beardswroth's Syncomatic plugin.  John?

     
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  • quentinsf
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    3. quentinsf,
    Apr 4, 2012 7:28 AM   in reply to Dorin Nicolaescu-Musteață
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    Thank you, Dorin - very useful answers!

     

    It's a pity that, when you have one of these big DNGs, and you convert to another version of DNG, it doesn't really change the size.  It doesn't matter whether I do it from within LR using Library > Convert photo to DNG, or File > Export, or do it externally using the DNG converter.  The result is always around 64MB.  I apparently need to convert from the original RW2 files to get a reasonable file size.  This sort of thing makes me think that keeping those may be a safer solution than keeping DNGs.

     

    For recent photos I still have the RW2s on my SD card, and it looks as if Syncomatic might be the answer - thanks!  For older photos, I'll save the unimportant ones as JPGs and the important ones as gigantic DNGs.  For the future... Mmm. I'm not sure... Maybe a more recent DNG format.

     

    This is from a Panasonic Lumix GH2, by the way.

     

    Many thanks!

    Quentin

     
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  • Dorin Nicolaescu-Musteață
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    4. Dorin Nicolaescu-Musteață,
    Apr 4, 2012 8:43 AM   in reply to quentinsf
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    It's a pity that, when you have one of these big DNGs, and you convert to another version of DNG, it doesn't really change the size.

    Of course, it's converting from already demosaiced data. The original bayern pattern mosaic is gone! You need to reconvert from the originals, if you wish.

     
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  • quentinsf
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    5. quentinsf,
    Apr 13, 2012 10:50 AM   in reply to quentinsf
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    OK - many thanks all.

     

    I also found the following earlier threads where people had similar issues:

     

         http://forums.adobe.com/message/3333887#3333887

     

         http://forums.adobe.com/message/2152395#2152395

     

    I think the moral of the story is always to keep what the camera shoots. You can convert it to DNG later if you need to, but you can't convert back (unless you embed the original in your DNG).

     

    But since my experience so far is that RAW files for the major manufacturers are more portable, faster, and more flexible than DNGs, they probably make for a better short-term archive format.

     

    Thanks for all answers.

     
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  • -Agfaclack-
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    6. -Agfaclack-,
    Apr 13, 2012 10:57 AM   in reply to quentinsf
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    quentinsf wrote:

     

     

     

     

    But since my experience so far is that RAW files for the major manufacturers are more portable, faster, and more flexible than DNGs, they probably make for a better short-term archive format.

     

     

    well it depends... DNGs for my canon cameras are smaller as the original CR2 files.

    and some programs i use don´t support CR2 but they support DNG.

     
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