5 Replies Latest reply: Feb 27, 2008 1:19 PM by Lee Jay-7OQGJF RSS

    What exactly is XMP metadata?

    2drumstix Community Member
      Hello all,

      Could someone please explain XMP metadata?

      I work with RAW in Lightroom, 1.3.1. Have all my images in separate named folders on a dedicated internal drive (D). I back up my Lightroom catalog and previews that is in "My Pictures" on the C drive, (the entire Lightroom folder basically), using a Seagate Auto backup program to an external firewire 750g drive, (works pretty well, no speed issues at all, just hums along backing up my every move, for those interested).

      Heres my questions.

      I understand Lightroom is not writing my changes to the actual RAW image file. And I'm not currently using write to XMP. So are all the development changes I make to an image being stored in the Lightroom folder with the catalog and previews?

      I understand metadata as information about an image i.e., camera, date, exposure and so on, what I dont understand is XMP metadata. With XMP write on, is a separate file being written and stored that contains data on the development changes I make to any given RAW image? If so, then I assume turning this on is a good thing. If I turn it on will LR go and try to write XMP for every image I've made changes too? or is it a start from now thing?

      thanks for your help,
      Don
        • 1. Re: What exactly is XMP metadata?
          Lee Jay-7OQGJF Community Member
          > are all the development changes I make to an image being stored in the Lightroom folder with the catalog and previews

          In the catalog.

          > is a separate file being written and stored that contains data on the development changes I make to any given RAW image?

          Yes.

          > If I turn it on will LR go and try to write XMP for every image I've made changes too?

          Yes, but it will take a good while. Best thing to do is to select all images, hit control-S (or the same menu option) and wait for that to complete. Then turn it on.
          • 2. Re: What exactly is XMP metadata?
            2drumstix Community Member
            are all the development changes I make to an image being stored in the Lightroom folder with the catalog and previews.
            In the catalog.
            So you are saying that with write XMP off, all changes I make to an image are already stored in the catalog?

            is a separate file being written and stored that contains data on the development changes I make to any given RAW image?
            Yes.
            So you are saying that with XMP on a seperate file is being written with data of image dev changes I make?

            If development changes are already being stored in the catalog, what is the benefit of using XMP to write a seperate file with dev changes?

            thanks.
            • 3. Re: What exactly is XMP metadata?
              Lee Jay-7OQGJF Community Member
              > So you are saying that with write XMP off, all changes I make to an image are already stored in the catalog?

              That's what I said, yes.

              > So you are saying that with XMP on a seperate file is being written with data of image dev changes I make?

              It's a separate file with RAWs, it's embedded into JPEGs, TIFFs, and DNGs.

              > If development changes are already being stored in the catalog, what is the benefit of using XMP to write a seperate file with dev changes?

              Backup for the database and the ability to sync and/or share those files and their changes.
              • 4. Re: What exactly is XMP metadata?
                2drumstix Community Member
                Thanks for the info.

                One more question. With XMP on, are your DEV changes stored twice? In the catalog and now as a seperate XMP file?

                Don