Deleting duplicate pictures on albums

Hi

Any image that has been placed in an album that is then deleted will (Obviously) also be removed from the album.

To clarify: If you have two duplicates of an image, place one in the album, and delete the other, then the album is unaffected. But if you delete the one you placed in the album it is removed.

You can use an AppleSceript provided by other users, How to find out the albums a photo is in: Jacques Rioux's Script, Catalina Version for Photos 5 - Apple Community, to find what albums a particular photo is in. That way you can then delete the duplicate that is not in the album.

The script compiled as an application can be downloaded from this tutorial site:  P01 - Applescripts from Photos’ User Tips Compiled as Applications  

You want an app that will identify the potential duplicates, put them in an album or mark them with a keyword for easy retrieval and deletion by you. You don't want one that does the deletion itself for obvious reasons. 

I've run tests on the these two apps with the following results and found them to be safe to use:

PowerPhotos - $29.95  

PowerPhotos is the iPhoto Library Manager version for Photos and is very powerful. Although more expensive I would recommend it as it has more capabilities than the others like the capability to merge Photos libraries or copy photos, both original and edited versions, along with their metadata between libraries.

PhotoSweeper - $9.99 - Demo version available.

PhotoSweeper compares bitmaps and/or histograms so it can detect duplicate images even if they have different file sizes, file names, image sizes and capture dates.

I don't think you should be using that app. It doesn't seem to be photos library aware, and might be identifying the thumbnails and previews stored in the libarary for every image as duplicates.

If you allow it to remove duplicates it will likely irreparably damage your library.

You must use an app designed to work with the photos library (Ie one that marks the photos or puts them in an album, and lets you review and then delete them within photos, rather than doing the delete itself.

Do NOT use a general file duplicate finder not designed to work with the photos library. They will damage your photos library and likely cause loss of your photos.

I personally use PowerPhotos (I also use this for copying images and data between libraries)
https://www.fatcatsoftware.com/powerphotos/


Another suitable app recommended by experts here is PhotoSweeper (I have no personal experience of this one)

https://overmacs.com/

Both are paid apps.

No. They don't provide a demo version as a few of the others have, limited to only searching a limited number of photos, and I'm not going to pay $30 to test.