To this point, our family photo collection has grown to a little less than 28,000 photos and videos: not totally unwieldy, but large enough that tagging and facial recognition are important tools for finding specific photos or groups of photos. Facial recognition also seems to drive a lot of Apple’s “Memories” features, which seem to have improved a lot in iOS 15.
Our library is also big enough that it contains plenty of unlabeled “People”—folks Photos can detect reliably enough to label, but with enough uncertainty that they aren’t given a positive identification. Sorting through this sub-collection ends up being really useful because about 10% of our total library falls into this category, where faces are detected but not identified.
Before, I used to scroll through sections of our library and label photos as I found them, but it turns out that it’s possible to create an album that automatically collects all of these together: Just create a Smart Album where the “Person” is set to the empty string:1
Because this approach relies on Smart Albums it’s only available on the Mac, but it makes library tagging much easier—especially when combined with another hard-to-discover Photos feature. I have thousands of photos with unlabeled people, but many of these photos are correlated: the pictures of the same person, sometimes in the same setting. Photos doesn’t make it easy to determine when this is the case, but, in some cases, you can double-click on a detected-but-not-identified face in the Info panel (⌘+I) and view a page collecting all the times this person appears. By renaming this unnamed individual, all of their photos are then merged into the correct identity. Super useful.