@phoneboy It’s because of problems like that, that I no longer use photo ‘libraries’. One gets trapped. Moving away becomes daunting. I’m currently using an app called ‘Duplicate File Finder’ from Nektony. It’s really good. As well as handling exact copies, it has some features to help you with similar folders and similar files. It does let you triage photos in Apple’s 'Photos' as well, though I’ve not tried that because I’ve never used 'Photos' on this machine. Problem is…. the app’s free trial only lasts two days. Might be good for you though because the 'Photos' triaging feature works in the free version and it works on similar pics as well as exact copies.