About the Duplicate Detection in Photos 5.0

The early versions of Photos have only been searching for duplicates on two occasions:

• When importing new Photos to the Photos Library: We might see an alert, if we try to import an exact duplicate of a file, that already has been imported. We can now decide to skip this duplicate.
• When syncing with iCloud Photos: Photos is searching for duplicates, when we are syncing photos and videos from several devices with iCloud Photos. If we upload the same photos from several devices to iCloud, Photos will keep only one master file in iCloud.

Given this filtering on import and upload, there should not be any duplicate, identical original image files in our Photos Library, unless we force Photos to import the same file twice. But there may still be very similar photos - multiple edited versions of the photos, downsized versions imported from Shared Albums, or similar. Or very similar photos taken as a burst in quick succession. To find similar photos we have to search manually or use third party duplicate finders. Some third-party tools can damage our Photos Library: Using third-party apps to remove duplicate photos might damage your Photos for macOS library - Apple Support

Photos 5.0 on Catalina has a new feature. Below the "Days", "Months", "Years" in the Photos view we may be seeing this message in a long loop of related messages:

This suggests, that Photos is searching for duplicates to help us to remove them. But this a not the case. Photos 5.0 on Catalina is detecting duplicates, so it can present the photos in the Days without duplicates and similar photos. But it will not remove duplicates, it it just brushing the duplicates and similar photos below the carpet and keeping them out of sight for a more compact presentation.

As described in the Catalina Preview: https://www.apple.com/au/macos/catalina/

"Focus on your best shots.

Photos has a new immersive, dynamic look that showcases your photos and memories. See only the best shots in your library, without the duplicates and clutter. Browse your favourite photos by days, months and years, and get larger previews of all your photos. And Photos is even smarter, so it can highlight important moments like birthdays, anniversaries and trips."

And:

https://www.apple.com/au/macos/catalina/features/

“Your best shots

Photos intelligently showcases the best shots in your library, removing duplicates and clutter.”

But there are no albums, where the duplicates are collected to help us to remove them easily. They are just collected for Photos's internal use.

But we can use the "curated" Days as a starting point to detect duplicates with a smart album, that is showing us the suppressed photos and videos.

We can create this smart album indirectly in two steps:

• First we create an album from the curated photos for a particular day:
  • We select all photos of this day in the day view and use the command File > New Album from selection - call this album "Curated".
• Then we create a smart album to find all photos that have been skipped by the curation.
  • File > New smart album
  • Set the rules to Match all
  • Album is not "Curated"
  • Date Captured is ...

For example: I collected all photos from the Day view of September 4 in one album "curatedMoremi Game reserve"..

My Smart album for the skipped photos is set up like this:

It contains all 34 photos, that are not shown in Photos > Days, possible duplicates or similar photos, a good starting point to search for redundant photos.