I back up my iPhone to my iMac using USB. I do not use iCloud for photos (iCloud is turned off on both devices for photos). At first, I synched my entire photo library from my iMac onto my iPhone, but the iPhone storage filled up and now I want to have just the last year of pictures. However, even when I specify "last year" only, ALL my photos remain on the iPhone. Why are the older photos not being removed, and how can I fix this?
iPhone SE
OK, I found out that I had to sync and unsync and sync and unsync a bunch of times, each time specifying a small range ("last year") and then unsynching (it asks if I want to remove all photos, and each time I said yes), and then very gradually (took about two hours), it whittled down my photos from about 60 GB to just the last year of photos (~5 GB). As markwmsn suggested, I also had some duplicates (photos that were shared with me) that I had to manually erase (they had trash can symbols that I could select, and then delete). So now my phone has storage space again. Whew
OK, I found out that I had to sync and unsync and sync and unsync a bunch of times, each time specifying a small range ("last year") and then unsynching (it asks if I want to remove all photos, and each time I said yes), and then very gradually (took about two hours), it whittled down my photos from about 60 GB to just the last year of photos (~5 GB). As markwmsn suggested, I also had some duplicates (photos that were shared with me) that I had to manually erase (they had trash can symbols that I could select, and then delete). So now my phone has storage space again. Whew
...PS: I was able to speed up the re-syncing process by specifying just the "last week" of photos. Then, once my phone was clean, I re-synced the "last year" of photos.
When you "synch" your library from your Mac to your iPhone using Finder, it is really only a blind copy. It does not take into account any copies that might be on the phone already, so you may have duplicates. Reducing the range of photos "synched" (such a specifying "last year" in your case) will reduce the duplicates, but it will not remove any photos that were still on the phone since you took them.
Does that help explain what you have experienced? (It would not apply if you have been deleting photos from your phone after transferring them to your Mac.)
Cannot remove synced photos from iPhone
