Today’s Question: If you haven’t previously enabled the option to saved metadata to XMP in Lightroom Classic, can you do this after the fact to old photos?
Tim’s Quick Answer: If you enable the option to automatically write metadata updates to your photos in Lightroom Classic, that will take effect for all existing images automatically. You can also use the option to manually save metadata if you want to be sure the task actually completed.
More Detail: By default, Lightroom Classic only saves metadata updates to the catalog, not out to the actual image files on your hard drive. However, you can enable an option to have metadata updates saved automatically to the images as well. Note that for proprietary raw captures the updates will be written to an XMP “sidecar” file, while for other image formats the metadata will be written directly to the source image file.
To enable the setting, first bring up the Catalog Settings dialog by choosing Lightroom Classic > Catalog Settings on Macintosh or Edit > Catalog Settings on Windows. Go to the Metadata tab and turn on the “Automatically write changes into XMP” checkbox. You can then close the Catalog Settings dialog.
Once this checkbox is turned on, Lightroom Classic will immediately start updating the metadata for all photos in your catalog. However, you won’t see a progress indicator for this task. If you’d like the confidence of knowing the metadata was updated completely, you can use the manual approach.
Start by going to the All Photographs collection found in the Catalog section of the left panel in the Library module. Make sure no filters are set, so that you’re viewing all images. Then choose Edit > Select All from the menu to select all photos in your catalog. Finally, choose Metadata > Save Metadata to Files from the menu to initiate the process of updating the metadata for your source image files. You’ll see a progress indicator on the identify plate at the left side of the top panel.
Keep in mind that only standard metadata information, along with adjustment settings from the Develop module, are written to metadata with this process. Lightroom-specific features such as collections, virtual copies, and pick/reject flags are only saved in the catalog, because they are not part of an established metadata standard.