13 Replies Latest reply on Jun 13, 2007 7:38 PM by (Micah_Tan)

    A way to overwrite DNG files instead of creating additional files?

    Level 1
      I did a search for overwriting DNG files when making some basic edits (e.g. white balance) but I only found a reference to a feature request.

      The main reason I'm asking is that I want to be able to set WB and save that edit into the DNG and have:

      1. No extra sidecar file.
      2. Machine/program independence (be able to copy to another computer or program and be able to read the changed setting).
      3. Not create a "duplicate" file: e.g. filename.dng and filename_1.dng

      I can't seem to do it w/the version of ACR in PS2. Does anyone know how to do this in PS2's ACR, or if this is available in PS3's version of ACR?

      Thanks.
        • 1. Re: A way to overwrite DNG files instead of creating additional files?
          JimHess-8IPblY Level 3
          Both Photoshop and Camera Raw treat raw files and DNG files as read only. While it's true that Camera Raw writes adjustment changes directly to the DNG file instead of writing them to an XMP sidecar file, it is not possible to overwrite the file. The alternative is to make the changes and use the save feature in Camera Raw to save a new DNG file with the new settings. Then Cancel from Camera Raw to preserve the original image as it was.
          • 2. Re: A way to overwrite DNG files instead of creating additional files?
            Level 1
            >The alternative is to make the changes and use
            >the save feature in Camera Raw to save a new DNG
            >file with the new settings.

            Jim,

            This is what I'm seeing, and is exactly what I don't want to happen. I suppose that I could always clean up the old files after the fact, but I'd prefer not adding an extra step to my workflow.

            Thanks for your input.
            • 3. Re: A way to overwrite DNG files instead of creating additional files?
              Level 1
              I believe I've heard talk that a future spec for DNG will include multiple adjustment settings -- basically several versions of an image in one file. That certainly can't come soon enough
              • 4. Re: A way to overwrite DNG files instead of creating additional files?
                Level 1
                > "Both Photoshop and Camera Raw treat raw files and DNG files as read only. While it's true that Camera Raw writes adjustment changes directly to the DNG file instead of writing them to an XMP sidecar file, it is not possible to overwrite the file".

                What does that mean? Given that they are writing XMP metadata into the DNGs, they are obviously not treating them as "read only".

                I'm not sure what it being asked for here that isn't available. Perhaps:

                > "Machine/program independence (be able to copy to another computer or program and be able to read the changed setting)."

                Only Lightroom understands ACR's settings - the XMP really records the slider-values, and they only make sense to a program with the same sliders.

                If what is being asked for is a change to the raw image data in the DNG based on the edits - that won't happen. I suspect it is impossible even in theory to identify what raw image data would correspond to a given set of settings in ACR - there may simply be no such set of values.
                • 5. Re: A way to overwrite DNG files instead of creating additional files?
                  JimHess-8IPblY Level 3
                  Barry,

                  I knew someone would catch me on that statement. That is why I tried to qualify it. And now that I think about it, maybe I am a little confused. Camera Raw writes the changes to the DNG file directly to the file without changing any of the pixel data that is contained therein. So when a DNG file is re-saved I guess the pixel data is saved again as well, although they have not been altered. So I apologize for my misinformation. Thank you for making me think about the process a little more.
                  • 6. Re: A way to overwrite DNG files instead of creating additional files?
                    Level 1
                    > "So when a DNG file is re-saved I guess the pixel data is saved again as well, although they have not been altered".

                    I believe (I can't remember where I saw it) that in fact the XMP data in a DNG file can be re-written just by overwriting the first few blocks, rather than having to re-write the whole lot. That is how you can write metadata to 100s of DNGs very fast.

                    But, it still isn't a read-only file - just a not-very-much-written file.
                    • 7. Re: A way to overwrite DNG files instead of creating additional files?
                      michael shaffer Level 1
                      > it still isn't a read-only file - just a not-very-much-written file.

                      Just to be accurate ... is "read only" the correct term in this case. That is, "read only" is OS terminology that would imply the file cannot be changed at all. Others have referred to ACR reading/writing of DNG files as "non-destructive", which refers only the raw data and not the XMP.
                      • 8. Re: A way to overwrite DNG files instead of creating additional files?
                        Level 1
                        >I'm not sure what it being asked for here that isn't available. >Perhaps:
                        >"Machine/program independence (be able to copy to another computer >or program and be able to read the changed setting)."
                        >Only Lightroom understands ACR's settings - the XMP really records >the slider-values, and they only make sense to a program with the >same sliders.

                        Barry,

                        The main reason I'm asking is white balance, which I'm fairly certain is in the DNG file itself and understood by multiple programs.

                        ACR can obviously set this value -- I just want it written into the original DNG file instead of having a duplicate DNG file created.

                        As far as I'm able to tell, Bridge, Lightroom, and Expression Media can read the new WB setting. I haven't yet tried the browser in DXO. As for the other XMP settings, I'd prefer that they were applied, but I understand that different programs have different features. White Balance, however, seems pretty universal.
                        • 9. Re: A way to overwrite DNG files instead of creating additional files?
                          Level 1
                          > "The main reason I'm asking is white balance, which I'm fairly certain is in the DNG file itself and understood by multiple programs. ACR can obviously set this value -- I just want it written into the original DNG file instead of having a duplicate DNG file created".

                          I DO get it written to the original DNG file. I have done since I upgraded to CS2 in May 2005. It is written as XMP metadata: namespace "http://ns.adobe.com/camera-raw-settings/1.0/"; crs:Temperature>7150; crs:Tint>+2.

                          I'm puzzled - what makes you think you are NOT getting it written to the original DNG file?

                          (Very few products will understand the way Adobe write the WB as XMP metadata in the DNG file. This XMP namespace isn't universal).

                          I have a feeling that what you are requesting is (in effect) that, when you change the WB from what was set in the camera, Adobe not only puts the new value into the DNG as XMP metadata, but also changes the metadata recording the in-camera WB, (AsShotNeutral or AsShotWhiteXY). These would then be understood by products that can't interpret Adobe's XMP metadata for the WB.

                          Are you saying that THIS is written if you duplicate the DNG, but not if the DNG isn't duplicated? I would be surprised if Adobe software ever changed these values as a result of editing in ACR (or Lightroom). Is there evidence that they do?
                          • 10. Re: A way to overwrite DNG files instead of creating additional files?
                            Level 1
                            >I DO get it written to the original DNG file. I have done
                            >since I upgraded to CS2 in May 2005. It is written as
                            >XMP metadata: namespace
                            >"http://ns.adobe.com/camera-raw-settings/1.0/"; >crs:Temperature>7150; crs:Tint>+2.

                            Barry,

                            When using the ACR dialog, I open up the DNG, change the setting and click "Save...", and in the resulting, hit "OK" after making sure the output is still DNG. This results in a duplicate DNG with a numeric suffix appended.

                            I'll run through some more testing later (pulling up multiple files in filstrip mode, clicking "Done" instead of "Save...", etc.) and see if I can duplicate your results.

                            Which steps are you using to embed the WB into the DNG?
                            • 11. Re: A way to overwrite DNG files instead of creating additional files?
                              Level 1
                              > "Which steps are you using to embed the WB into the DNG?"

                              "Open" (in Photoshop) or "Done".
                              • 12. Re: A way to overwrite DNG files instead of creating additional files?
                                JimHess-8IPblY Level 3
                                As Barry has mentioned, when you are finished editing your DNG file you need to click on the "Done" button to apply those changes to the original file. Since the DNG cannot be overwritten, if you try to save it the only thing Camera Raw can do is create a duplicate file.
                                • 13. Re: A way to overwrite DNG files instead of creating additional files?
                                  Level 1
                                  Well, I figured out which settings I need. I set ACR to update full-sized previews on modification, and all is well. I also set the DAM application (Expression Media) to use the previews.

                                  Alternatively, I was able to set EM to not use the previews and it was able to display the images correctly using the modified embedded XMP settings in the DNG file.

                                  Thanks Barry and Jim for your help.