When opening Lightroom TIFF in Photoshop, something other than metadata has changed?

Discussion in 'Digital Darkroom' started by russellcbanks, May 16, 2022.

  1. I keep getting this message when using Lightroom to open a TIFF file I’ve edited in Photoshop:

    "This photo has been changed in an external application. Should Lightroom overwrite the settings on disk?"

    I searched this forum (and everwhere else via Google) and found many references to "metadata has been changed," but this message just says the "photo" has been changed. My working procedure is to:

    1 Make initial "camera raw" adjustments to the DNG in Lightroom
    2 Open that DNG in Photoshop
    3 Edit with adjustment layers, clone-stamp, etc.
    4 Save as TIFF and close the file
    5 Later, return to do more work on the file by selecting it in Lightroom, then Edit in... Photoshop, ticking the "Edit Original" button.
    6 As the file is opening, I get this "photo has been changed in an external application" message, SOMETIMES, but not always.

    What causes this? I’m not doing anything to that TIFF in Lightroom that I’m aware of. At that point I’m just using Lightroom to catalog it with the rest of the shoot. And if something changed in the metadata, wouldn’t that get the metadata changed message? I’m concerned that something other than the metadata is being changed, without my direction (presumably the image itself!).

    Should I select Cancel (where it apparently opens without overwriting) or let Lightroom overwrite the settings on disk?


  2. digitaldog

    digitaldog Andrew Rodney

    Step 2 is done exactly how? Ideally you want to use the Edit In Photoshop command. That will pass off the raw (DNG) and instructions to ACR which renders the image and presents it to Photoshop proper. Then you edit and simply use Save. The new (if selected in preferences, TIFF) ends up in the catalog next to the DNG. If you want to edit that NEW TIFF, you can of course do so from LR. IF the TIFF has layers and you've done any edits in LR, it has to do this on a flattened 'version' and when you ask to open it back into Photoshop, well that isn't the original TIFF.
    The 'error' isn't a big deal anyway. LR detects a change in the metadata from what it last saw and asks you to update this for it. But its not something you should be seeing if you use LR to hand off data to PS and back again.
    mikemorrell likes this.
  3. Yes, what you've described is exactly the way I do it. The TIFF I save and close ends up in the catalog next to the DNG. I don’t do anything to the TIFF in Lightroom (that I know of)... no adjustments in the Develop module, no metadata changes... So I’m puzzled about what Lightroom thinks it might want to "overwrite." But, like you say, it’s probably not a big deal if all the LR develop settings remain zeroed.
  4. I have this from time to time, but my workflow is sufficiently varied that I haven't isolated when it happens.

    This might be useful: Metadata Mismatch – Ask Tim Grey
  5. digitaldog

    digitaldog Andrew Rodney

    It's also possible something, somewhere else might be touching the metadata of the TIFFs? This is what LR is asking you. It 'sees' that its understanding of some metadata it tracks, differs from the document and so it's asking you "you want to update or write 'my' metadata back?".
    Only TIFFs, only after the Edit In useage?
  6. I've no experience of this problem, I sometimes edit a Lightroom (RAW) photo in PhotoShop which (as @digitaldog mentions) results in a .tiff file in Lightroom. As far as I know, the meta-date in the .tiff file is preserved. I've never used DNG.
  7. This isn't because of the DNG format. I shoot Canon and Panasonic, so none of my raws are DNG, and I've had it happen. However, I usually only notice it later, so I'm unable to reconstruct exactly the workflow.
  8. If the metadata's being changed, wouldn’t I get the "metadata has been changed," message? The one I’m getting says the "photo" has been changed (nothing about metadata).

    If it IS the metadata that’s changed, I want Lightroom to overwrite, since that’s the only thing I use to edit metadata. It's interesting that the "warning" dialog offers a don’t show this message again checkbox, which would seem to indicate it’s not a big deal whether or not you see it.

    As others have observed, this happens intermittently, so it’s hard to troubleshoot. I opened the file that was giving the message when I started this thread, and when the message came I let Lightroom overwrite as it loaded into Photoshop. I added an adjustment layer, saved and closed. Then opened again from Lightroom and didn’t get the message. Since it appears innocuous, I’ll just tell it to not show the message in the future.

  9. digitaldog

    digitaldog Andrew Rodney

    The error message is telling you that Lightroom has determined that the document(s) were changed outside of Lightroom after they were imported. Only if you know that is not the case and the metadata shown in the Library module along with any Develop adjustments is correct then you can choose the overwrite setting.
  10. Thanks for clarifying!
  11. It is hard to tell remotely, but it might be that it is updating the modification time for the file, not changing the file itself.

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