How to delete photos on iPad but save them on a Mac

Lahague wrote: … if I turn ICloud back on it will synch photos back to all devices, won’t it.?

Yep-- that's what synchronize means, and that's the purpose of iCloud. On my iPhone I have "Optimize Storage" turned on in Settings>Photos. In that case, pictures can occupy as little as 10% of the storage space they take otherwise. It works by keeping smaller pictures, more like the size of an iPhone screen, on the phone. When you want to zoom in or edit, Photos grabs the full sized picture from iCloud. It's pretty slick. But as long as you use iCloud Photos, then every connected device will have exactly the same pictures in their Libraries.

Another option, one that I use, is to have more than one Library on the Mac, syncing one of them but not the other. So only the synced Library is synchronized with iCloud and the iPhone. You have to manage two independent Libraries, and maybe copy pictures back and forth, but it's something to think about.

Turn off iCloud on both your devices, then delete pictures on the iPad.

You didn't say what you wanted to do about iCloud afterward. Do you want your Mac to sync with iCloud or do you want your iPad to sync with iCloud?

Lahague wrote:

Thanks for your reply. I want to store all my photos on my Mac and free up space on my phone and iPad by deleting many photos. I want to maintain iCloud on all devices but if I turn ICloud back on it will synch photos back to all devices, won’t it.?

You can either take over full operational control of your photo library hosted on that Mac and cable-synced from that Mac to your devices and cable-imported from devices into the Mac photo library, or you can enable and use iCloud Photos and allow it to maintain and to cache media (and “optimize”) as it sees fit.

There are likely also third-party photo management apps around, if neither of these options meets your requirements.

The following can be used to cause iCloud Photos to “optimize storage” on a particular device:

Manage your photo and video storage - Apple Support