I have both my iPad and iPhone uploading to the same iCloud account with the top box checked in System Preferences. (Automatically upload and safely store all your photos.....)
My home iMac Only has the Shared Albums checked, bottom box
Question is, if I check the top box iCloud Photos, will it combine or over-ride what is already there?
Just Nervous... thanks
When you enable iCloud Photos on an additional device, the Photos Library on this new device will be merged into the existing iCloud Photos Library -all photos and videos, all albums and folders. Photos will be checking for duplicates and try to solve conflicts between duplicates. You may still see some duplicates, if a photo or video has been edited differently on the devices, or the titles, captions, keywords are different. Albums may vanish temporarily during the merging, but should reappear later. But you should not lose any photos or videos. But I would make a current backup of your Mac before enabling iCloud Photos. I would also save a copy of your Photos Library on a separate drive, so you can revert to the current state, if something should go wrong.
When you enable iCloud Photos on an additional device, the Photos Library on this new device will be merged into the existing iCloud Photos Library -all photos and videos, all albums and folders. Photos will be checking for duplicates and try to solve conflicts between duplicates. You may still see some duplicates, if a photo or video has been edited differently on the devices, or the titles, captions, keywords are different. Albums may vanish temporarily during the merging, but should reappear later. But you should not lose any photos or videos. But I would make a current backup of your Mac before enabling iCloud Photos. I would also save a copy of your Photos Library on a separate drive, so you can revert to the current state, if something should go wrong.
See the article Change preferences in Photos on Mac - Apple Support
When iCloud box is checked in photo preferences of Mac , the photos with full resolution saved in iCloud will sync with iPad / iPhone see the article Set up and use iCloud Photos - Apple Support
When you turn on iCloud Photos, your photos and videos automatically upload to iCloud. They're not duplicated in your iCloud backup,
Read this article My Photo Stream - Apple Support
The photos from My Photo Stream on your other devices aren't affected. Photos from My Photo Stream stay on the iCloud server for 30 days from the date you upload them to My Photo Stream. If you sign in to iCloud with the same Apple ID and turn on My Photo Stream on another device, the photos automatically download.
The photos that synced From iPhone / iPad to iCloud will also simultaneously synced with Mac when signed in with same Apple ID and password on the same network Use iCloud Photos to store photos in iCloud - Apple Support
Any new photos you add to Photos or take with an iOS device appear on all your devices that have iCloud Photos turned on. Your photos and albums are organised the same way on every device, and if you make edits or remove items, you see the changes on all your devices.
tygb, thanks for your input.
So, if I click on the iCloud Photos box, it will just add these to what's in my current photos in iCloud and not replace them?
Sorry, just don't want to lose pictures.....
Multiple Devices on iCloud photos - adding a new device
