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Camera Raw Fan
Camera Raw Fan
Known Participant
January 13, 2022
Question

Enhanced DNG - WHY so large?

  • January 13, 2022
  • 4 replies
  • 4231 views

I keep getting this question, and I have read through Adobe's literature, but I cannot seem to get a clear answer on this question:

 

Why are Adobe Enhanced DNG raw files so large in comparison to the native raw file, or a standard DNG raw file?

 

I am thinking that the Adobe Enhanced raw file is packaged also with the enhanced raw data as well. And when the image is actually rasterized, then it is applied? And even before that, it is applied to the preview that we see in Lightroom when we are making adjustments.

 

Thank you for as much detail as possible so I can help others understand.

4 replies

Y
Yona24866456x8o1
Participant
June 29, 2023

There's an easy way to apply the lossy DNG compression to images, which will greatly reduce the size of enhanced images as well as other uncompressed raws at the cost of a slight quality loss:

 

  1. Select your enhanced images (I text filter for "enhanced"):
  2. Libary | Convert Photos to DNG
  3. Uncheck "Only convert Raw files"
  4. Check "Delete originals after successful conversion"
  5. Check "Use Lossy Compression"
  6. Click OK

 

For me, files often go from 100-200MB to 20-30MB, almost a 10x size reduction, at no preceptible quality loss.

    Jim Wilde
    Community Expert
    Jim WildeCommunity Expert
    Community Expert
    January 13, 2022

    Even without using the Super Resolution option, the Enhance function generates a Linear DNG, which is no longer a raw file and contains demosaiced data. As such it's akin to a Tiff file, with at least 3 times the amount of data of the original raw file. If you then add Super Resolution into the mix, you'll see another 3-4 times increase in the file size. On my system, a 36MB raw file increased to 146MB when using just Enhance, and then to 436MB when I used the Super Resolution option.

     

    All as expected.

      Camera Raw Fan
      Camera Raw FanAuthor
      Known Participant
      January 14, 2022

      Sorry for not being more clear, but I do not use "super resolution." Your answer here is getting to the root of my question.


      So my next question is: is a "raw details" image still raw?

      Is it still "lossless" (parametric edits vs pixel edits) in the way that we consider raw files lossless?   


      It does not at all seem to be rasterized.  Further adjustments on it in Lightroom/Camera Raw do not react like a typical rasterized/pixel editing Tiff or other rasterized file format would merely using the Camera Raw Algorithms, or the Camera Raw Filter on a pixel image...

       

      This leads me to think that the demosaiced information in a "raw details" DNG ("Enhanced") is stored along with the original raw data, and that it remains lossless/raw information until the image actually gets flattened (or rasterized). 


      Side Note: I have read the Digital Negative (DNG) Specification (PDF) about it.  It might just be me, but simply speaking, it seems a little ambiguous whether "raw details" is still raw?

      Thank you ahead of time for taking the time to reply!  👍

        Ian Lyons
        Community Expert
        Ian LyonsCommunity Expert
        Community Expert
        January 14, 2022

        > This leads me to think that the demosaiced information in a "raw details" DNG ("Enhanced") is stored along with the original raw data, and that it remains lossless/raw information until the image actually gets flattened (or rasterized). 

         

        The demosaiced information (i.e. the original raw file) does not appear to embedded in the 'Enhanced-DNG' file. If it is, then it would be easy to extract same using the DNG Converter 'Extract' option, and having just tried it, I get the following.

         

         

        DdeGannes
        Community Expert
        DdeGannesCommunity Expert
        Community Expert
        January 13, 2022

        See the screen capture when you use the "Enhance" feature in LrC with a RAW image file. As you can see from the info in the dialog the is going to be enhanced to produce more detail during this process the number pixels in the hight and width will be doubled, if Super Resolution is chosen, which means the total pixels will be quodrupled. If the raw file is 24 mega pixels the enhanced DNG will have 96 mega pixels.

         

        Regards, Denis: iMac 27” mid-2015, macOS 11.7.10 Big Sur; 2TB SSD, 24 GB Ram, GPU 2 GB; LrC 12.5,; Lr 6.5, PS 24.7,; ACR 15.5,; (also Laptop Win 11, ver 24H2, LrC 15.3; PS 27.0; ) Camera Oly OM-D E-M1.
        Camera Raw Fan
        Camera Raw FanAuthor
        Known Participant
        January 14, 2022

        I am only talking about "Raw Details" or what we used to call "Enhanced Details" as I never use "Super Resolution." 

          Sean McCormack
          Community Expert
          Sean McCormackCommunity Expert
          Community Expert
          January 13, 2022

          If you're checking Super Resolution, you're increasing your fine pixel dimensions by a factor of two in each direction. If you're just using Raw Details, it's potentially that your Raw is compressed and the new file has more detail, simply making it it larger due to that. 

           

           

          Sean McCormack. Author of 'Essential Development 3'. Magazine Writer. Former Official Fuji X-Photographer.
          Camera Raw Fan
          Camera Raw FanAuthor
          Known Participant
          January 14, 2022

          Sorry about not being more clear. I am only talking about "Raw Details" or what we used to call "Enhanced Details" as I never use "Super Resolution." 

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