Over time Apple realized too many people were mucking around, so they came up with a solution to the problem.
Any thumbnails needed by i Photo (for low-res views in grid mode) will get recreated by the program if they are missing.Don’t Edit or Prune the i Photo Library Directly The i Photo Library on the disk is a collection of nested folders and files, containing your original photos, edited versions, thumbnails, .i Photo Duplicate Annihilator is a simple application that helps do just what it says, for only US!The program scans the pictures in your library and tags all duplicate copies it finds by putting “duplicate” in the comments.Any events or rolls in your library that are labelled as can also be safely deleted.
Most of these appear when you import one i Photo library into another rather than doing a clean merge.Six copies of the Thanksgiving dinner, three of last summer’s vacation, and all these thumbnails all over the place. Apple does not provide a way to remove duplicates directly within i Photo.Why after of the program they can’t include this feature is a mystery, but fortunately another handy utility comes to the rescue.Whether you import one photo or a few hundred, each is a separate roll. Since i Photo ’08 Apple has included an organizational tool called Events which helps simplify the grouping of photos. However unlike rolls, events can be merged by dragging one event on top of another, or selecting both events and choose You can repeat the process as needed, eventually consolidating your library into a smaller group of events to manage.Once merged, related photos can be viewed in one place and unneeded items pruned out.I’ve worked with quite a few clients who have tried a bit of de-duplication and pruning of their i Photo libraries to free up disk space, and wound up with a bigger mess than when they started.