Splitting iCloud Photos

Hi there,

Similar to a question asked by eeperman some time back, I have set up a new ID for myself, as previously everything (contacts emails etc.) had all been shared under the one user. I have managed to successfully transfer everything except photos (by e.g. sharing all the notes that were mine, and then copy pasting them, and then deleting them in the original joint cloud). However, with the photo's this doesn't seem to work. I have a large swathe of photos which I am now sharing (fine), but also a large swathe which I want under my ID, but not in the shared folders and cannot manage to do the latter, even after downloading them, I cannot copy or make myself the "owner" of the photos. Have you any guidance on how to do this, thank you!