Performing any action resets the capture time to now

Thanks for the replies. I got home and tried some things:

• I checked exiftool and found that the original images from the scanner didn't have the capture time metadata. So LR does indeed indeed use the modification time if that's not there.
• LR correctly updates the capture metadata and exiftool's output says so
• Now, several photos later I couldn't make LR update the time incorrectly without my deliberate action to do using the actual function.

I even tried updating the capture time first, checking exiftool, then adding a caption, and LR grid view (of the time taken) didn't change (as it shouldn't).

I also went back to photos I distinctly remember I had corrected the capture time based on offline sources (in this case, writing on the back!), and saw it change when I add a keyword. Tonight I went back to that photo and added and removed key words and the capture time seemed OK.

Here is a link to the Dropbox: Dropbox - LR experiments - Simplify your life with a few experiments.

The only things I can think of since I can't reproduce the issue is some sort of memory leak or stability issue last night - since tonight I had it open fresh; or I was hallucinating.

anthonix  wrote On certain photos, performing any action - rotate in grid view, adding a caption, adding a keyword (haven't tried edits in Develop module) causes Lightroom to reset the capture time to the current date and time. On some photos, this doesn't occur though. For now, I'll leave the metadata saving turned off. Is this a known bug and has anyone had this problem? Thanks, Anthony

Not a bug. It is the image you are working with.

From what make and model camera did they come from?

Are they Scans of old film Negatives, Slides or Prints?

Are you doing this on import or after?

Writing out metadata will indeed alter the file modification date, as viewed from a file browser, but that is not the same thing as altering the capture date.

In Windows, the capture date metadata field for a recognised image format (JPG) has the name "Date Taken", and this field can be shown as a separate column in Details view. MacOS finder will, I am certain, have an equivalent of this.

Either this field was already filled in within the starting file, for example by a camera, or else not. I believe that if that info is found absent at import, Lightroom will take the file creation / modification details instead, and use those for capture details by default. These details can then be changed in LR, to whatever actual capture date is known.

In the example of a film scan: this is scanned one day, imported another day, further edited another day, none of these reflecting the date the original photo was taken onto film. One may need to refer to clues within the photo to determine this, and type that date into LR. LR then writes this back out as part of the external metadata - but doing this will NOT correspondingly alter the modification or creation details of the file itself, as viewed by a file browser: to be clear, if an original photo was exposed in 1900, a file containing a scan of this photo will not show "1900" in its file creation date, nor in its file modification date. It will show the dates scanned, and adjusted, respectively.

In the case of a camera JPG that is imported to Lightroom, each time you write out external metadata that renews the modification date/time of the JPG itself. Only the metadata section of the file has in fact been altered, but that is still a real change for the whole file so far as the operating system is concerned. The same thing applies for a Raw file if that is in DNG format.

A camera proprietary Raw format does not itself get altered by writing out metadata; this happens into a sidecar file alongside (with "xmp" file extension). Further updates to this are reflected by a change of the XMP file's modification date and time, even though again, this is only an update of metadata fields within that.

The capture date and time are part of this metadata, but themselves remain unaltered by writing that out. This same info shows in Library, in Info overlays, etc. Lightroom preferentially shows the capture details and not the file modification details, since the former is of main interest with a photograph. A file browser takes more interest in technical changes to a file: in that context one is not interested so much in what it's a picture OF; but rather, in whether each file requires backup, and other technicalities of that sort.

What kind of images? Are these perhaps scans, meaning there isn't really a 'capture time', only a file creation date and a file modification date? Writing metadata to such a file would indeed change the modification date.