1 Reply Latest reply on Jun 13, 2009 5:41 PM by JimHess-8IPblY

    Q:  are DNG files 100% same as original RAW?




      1.  i know this must have been asked before, but i didn't know how to search for the answer to my question. 


      2.  i currently have a hybrid system where i convert some of my RAW files to DNG and keep the original RAW files.   i got to thinking about this and what i'm going may not be logical thing to do etc...


      3.  here's the question:  are DNG files 100% the same thing as the original RAW file?    if it is, then i'll just convert all of my RAW files to DNG and throw away the original RAW files.     however, i have to assume that the DNG file is not 100% the same thing as a RAW file simply because if it were, then we wouldn't need all of the different "translators" to decode all of the various RAW files out there.   furthermore, each camera company claims (ex: Nikon) that their RAW convertors are able to best decode their NEF files since they understand everything that goes into the RAW file;  something that ACR and thus DNG can't accomplish (according to what they say).      anyway, thus i'm wondering if it is a rational process to keep the original RAW file, at least for those very important images.  


      4.  anyway, hopefully the above makes sense.   thanks for any thoughts. 



      harry shin

        • 1. Re: Q:  are DNG files 100% same as original RAW?
          JimHess-8IPblY Level 3

          DNG files are not 100% the same as raw files from the camera.  If they were there wouldn't be any point in having them.  However, the raw image data is precisely the same image data that was in the original raw file.  The DNG file is a different container that enables Adobe to "standardize" the raw format to a certain extent.  The different camera companies have some of their data that is proprietary and cannot be read by Adobe Camera Raw or Lightroom.  And this will vary from one camera manufacturer to another.  The DNG file format takes all of the adjustment data that can be read along with the original image data and stores it in a file that can be read by ACR and Lightroom.  Unlike the original raw images, the changes that you make to your DNG files are stored as metadata within the header of the DNG file rather than in a separate XMP sidecar file.  If ACR recognizes the camera that to the picture it will allow you to apply the appropriate specialized profiles created by Adobe.  These profiles are designed to stimulate the in-camera settings that are proprietary.  If your version of the ACR does not recognize the camera model then it has to make generic profiles available, but you can still use ACR to adjust your images.


          How you manage your raw images is a personal decision.  Some of the Adobe personnel seem to highly recommend converting to DNG.  The argument I have heard given is that they want to make sure their raw data is in a form that they will be able to work with in the future.  That argument does not seem to be as widely adhered to by a lot of users.