I recently turned off iCloud in order to change Apple ID. I turned it back on before the photos were deleted from my Mac #1. Now it wants to reupload, but has to compare the photos to what is in the cloud. I have a huge photos library of about 700GB. I want to turn off iCloud for photos on Mac #1, let the photos be deleted from the mac, and then cull photos from the photos library on another mac which has iCloud turned on, before turning the cloud back on for the original mac. My hope is to decrease the ultimate size of the library and I don't want to wait for it finish comparing the photos it thinks it needs to re-upload. Is there any reason this won't work, or is a bad idea? Thank you for any input.

  • I want to make sure I understand: you have 700Gb of photos stored in iCloud? (That's either a lot of photos, or a typo. Just checking!)
    – TMHahn
    Commented Jul 29, 2016 at 22:48
  • Sadly it is not a typo. I have lots of RAW, but also lots of duplicates. Duplicate finding software has trouble even loading the library, so I need to trim it first.
    – Bronwen
    Commented Jul 30, 2016 at 2:33
  • Do you have these photos backed up somewhere else (just in case)? I have a 1Tb external hard drive PLUS Dropbox as backups to my iCloud. What you're suggesting in the original post seems sound to me. But I wouldn't try it with something I had no backups for.
    – TMHahn
    Commented Jul 30, 2016 at 2:52
  • Yes, they're backed up to a Time Capsule, though that did not work for transferring them to a new mac, oddly enough, and I have them backed up to another external hard drive, not through Time Machine. I started to back up to DropBox, but the upload is so slow. Thank you for your comments.
    – Bronwen
    Commented Jul 30, 2016 at 14:34
  • There's no reason that shouldn't work, other than the fact it's going to have to redownload your library on mac #1 at some point.
    – tubedogg
    Commented Jul 30, 2016 at 20:02

1 Answer 1


It did eventually work. Mac #1 finally realized that there was nothing to upload and started downloading from iCloud. Now both macs are in sync with the pruned library.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .