Late Adoption of XMP


Today’s Question: I have used Lightroom Classic for years and have never checked the box to “automatically write changes into XMP” in the Metadata settings. I have over a hundred thousand photos. If I check this box, will all photos be subjected to this change? How long will it take? Will it affect my cloud backup?

Tim’s Quick Answer: When you turn on the “Automatically write changes into XMP” checkbox it will apply to all photos in your catalog and will work in the background. It won’t take very much time, and the files are quite small so it won’t have a significant impact on your backup.

More Detail: I recommend turning on the “Automatically write changes into XMP” checkbox, which can be found on the Metadata tab of the Catalog Settings dialog in Lightroom Classic. The checkbox is off by default, but I consider it advantageous to have the option turned on.

The primary reason I prefer to have this option enabled is that it provides a backup of your key metadata that you can recover from in the event of a corrupted catalog, for example. It also provides a degree of cross-application compatibility, such as enabling you to view key metadata values with other software such as Adobe Bridge.

When you turn this option on, Lightroom Classic will start updating all existing images in the background. In my experience even with a large number of photos the process takes less than thirty minutes. You can quit Lightroom Classic and the process will resume the next time you launch Lightroom Classic again.

The size of the XMP sidecar files for raw captures (or the increase in file size for other image types) is quite small, so updating a backup also won’t require significant additional space or time.

In other words, as far as I’m concerned there’s really no reason to leave this option turned off, and I recommend turning it on.