Organizing Photos...Help

iCloud will sync all your photos libraries across all your devices (if you have enough iCloud space - if you don't you'll need to take out a bigger subscription). It won't sync individual image files from the pictures folder, so you'll have to import them into photos first (file>import). DO NOT try to import the whole pictures folder - that will also try to import any other libraries you have in there which will cause a nightmare for you. Instead, either select just the image files as part of the import, or first copy them all (just the image files) to a subfolder using finder, and then import them from there.

You need to set up iCloud photos on each device, and leave it running (photos open - mac connected to power). It will then sync the photos libraries on all your devices. (all photos on all devices). Depending on how many images there are and how big the libraries are, this can take some time - measured in days, not hours.

If any of your devices don't have enough storage for that, you'll need to enable "optimise mac/phone/ipad storage in the iCloud settings. This will then only store small versions of the photos on that device. Full size version will always be in iCloud.

See

using iCloud photos

https://support.apple.com/en-gb/HT204264

So, ultimately you want to get to a place where you have a single library on iCloud Photos which is sync'd to all devices and multiple backups are kept.

I would do the following:

1. Make sure you have backups of all your photos. On your iPhone make sure iCloud backups is switched on. On your computers, go into Finder and open your Pictures folder and you should find your Photos library - it should have a suffix photoslibrary as below.

Simply make a copy (CMD-C) and store it wherever you wish, rename it Photos backup or something distinctive.

1. Open Photos on computer no.1. Open preferences from the menubar or by pressing CMD-[COMMA]. Ensure that 'Copy items to library' is ticked. At the top under library location, check that the file path corresponds to the copy of the library you have just made.
2. Click on the iCloud tab and make a note as to whether iCloud Photos box has been selected. Don't worry at this stage whether or not it is selected, just leave it as it is.
3. Within Photos, select import and browse to the folder/s within the Pictures folder that contain all of the photos you want to include in the library.
4. If iCloud Photos has already been enabled, as per step 2 above, then I would wait until the new photos have been sync'd with iCloud Photos before moving on to next step. You can check the status by selecting Library in the sidebar and then scrolling down to the bottom of the photos. This stage could take some time because not only are the photos being uploaded but iCloud checks for duplicates.
5. Go to computer no.2 and repeat the above 2 steps.
6. So you will now have potentially 3 different libraries on your 3 devices. Some of them may already be in sync if you have previously activated iCloud Photos.
7. For those devices which do not have iCloud Photos enabled go to each device and enable iCloud Photos, for the Macs you'll need to select 'use as system library' first. I would switch each one on and wait until it has completed its sync before moving on to the next device. iCloud Photos should then merge and de-duplicate your libraries and you should see the new photos downloading on your other devices. Normally this stage works without any problems, however, occasionally problems are reported where one library gets replaced by another and not merged. So it is important to make the backups of the libraries as mentioned above, just in case you have to repeat any steps.
8. You should now have a single merged library sync'd across all 3 devices. However, its important to remember that iCloud is a syncing service, not a backup service. Therefore, on one of your Macs, under the iCloud tab on preferences make sure you enable 'Download originals'. This will ensure that the library package contains all of your photos and not just the catalog. Make sure you back up this file. Ideally you should utilise Time Machine to backup your entire Mac and keep a separate copy of the library on a suitable USB drive.
9. Finally you may find that you still have a lot of duplicates in your library. This may be because 1 photo may be a slight crop of another or has been modified in some way and iCloud Photos may not pick this up. A very good package to use is Power Photos, but it is a paid app. PhotoSweeper is another one, but also a paid app. Please don't use other cheap programs that offer to remove duplicates as these can damage your library. The benefit of these 2 programs is that they identify possible duplicates based on criteria you set. You can then review the results and confirm whether or not to remove the photos.

Good luck!

I should have added, once you have all your photos in the library you'll want to organise the library, set up albums, etc. This is useful article to help you do this:

https://discussions.apple.com/docs/DOC-250002326