iCloud Photo Library start up

[astrodog]

I'm considering using iCloud Photo Library, but have some concerns about what is going to happen when I pull the trigger.
At present my photos 'system' is:
MacBook Pro running Photos - this is my master library.
Photos are most often taken with my iPhone, but also a DSLR and another digital compact - these are imported to the mac, and appear on the phone through Photo Stream.
I tend to cull the phone photos more heavily after they've imported to the mac.

So what I have is two different photo libraries - in general the iPhone library is a subset of the macs, but not completely.

If I switch on iCloud - will I get duplicates?
What happens to photos taken with the iPhone - do they still reside on the phone, and also the iCloud library?
Or is it just one library?
What happens to the photos on the iPhone currently?
I have a 512GB iPhone 11 Pro, so don't intent on turning on image optimising....

Thanks for any help anyone can give - the Photos library on my mac is the most important thing on it, probably one of our most precious possessions, so don't want to screw it! :O

Lee

 

[ApfelKuchen]

Consider iCloud Photos to be like iCloud Contacts or any IMAP email account (Google, Yahoo, Outlook, iCloud, etc.) - your master library resides in the cloud, and it is synced to each device signed into that account. Add/delete/edit from one device, it syncs to the cloud, and then from the cloud to your other devices. Once all your various on-device libraries have been merged into iCloud, you'll have one library. That library will be mirrored to all your devices.

Generally, you will not get duplicates. The most likely reason for getting duplicates would be if you changed the filenames on Mac after Photo Stream had pushed those images over to iPhone (or vice versa).

It seems you're assuming that iCloud Photos treats the libraries on Mac differently than the libraries on iPhones/iPads. Every device's library is treated essentially equally when added to iCloud - it can't assume which library is "master" and which is not. The resulting library will be the sum of both libraries.

What happens to the photos on the iPhone currently? That depends on whether you choose "Optimize Storage," or "Download and Keep Originals." You've said you intend to use Download and Keep Originals. Presuming the combined library isn't too large, we can assume the photos currently on your iPhone won't be going anywhere - but you'll also be getting whatever additional photos have been added from the Mac.

The thing is, there's no way for you to manually manage the size of your on-device libraries - since deleting an image deletes it everywhere, "Optimize Storage" is the only way to put a large library onto a small internal drive (and while plenty of Macs have 1TB and larger HDs, you'd be surprised at how many people have 128 GB Macbook Airs - space can be tighter on one of those than it is on a 128 GB iPhone).

Regardless of which option you choose, you'll have thumbnail copies of the entire contents of the library, so you can always browse its full contents. If you're using "Optimize Storage," if a full-size image is not currently resident on your device, it'll be downloaded automatically when you click to view it.

For the sake of backups - the easiest way to truly backup the library is to Download and Keep Originals on the Mac, and make a Time Machine (or other whole-machine backup) of the Mac. Now, if you Download and Keep Originals on both iPhone and Mac, you'll have two devices with full copies of the library... that's not normally considered a proper backup method, but it's not bad.

Note that when you're using iCloud Photos on an iOS device, those photos are NOT part of your daily automatic backup, regardless of whether you use Optimize Storage or Download and Keep Originals. Apple's assumption is that the photos are already in the cloud, so making a backup would be redundant (imagine that howls of anger, "Apple is charging me for backing up my photos twice!")

 

[astrodog]

Thanks for taking the time for such a detailed reply. I'm still thinking whether to do it yet....

 

[astrodog]

I started it off..... on both my MacBook Pro and iPhone.
Seems to be uploading reasonably.
I had a look in iCloud photos with a browser from work today, and there are a bunch of duplicates. Is this normal? Neither upload is finished yet - does the system upload all then trim out duplicates?
Does it wait until the uploads are finished before downloading images to devices?
Sorry - this is all poorly documented by apple....

 

[Pipper99]

I started it off..... on both my MacBook Pro and iPhone.
Seems to be uploading reasonably.
I had a look in iCloud photos with a browser from work today, and there are a bunch of duplicates. Is this normal? Neither upload is finished yet - does the system upload all then trim out duplicates?
Does it wait until the uploads are finished before downloading images to devices?
Sorry - this is all poorly documented by apple....

I'm reading through "Taking Control of iCloud" by Joe Kissel, and I'm still having a hard time understanding this topic. I have an 11 Pro Max with 512gb, and I have 292gb of photos/videos on my device. When I look at the storage on my iPhone, iCloud Photos says that I can save 3.31gb if I enable it: I thought that by enabling iCloud Photos and choosing to optimize storage that I could save much more space. Isn't this how people with 64gb iPhones and large photo libraries are able to use the smallest storage device?

How's it working out for you?

 

[astrodog]

It's going really well. My libraries were on the order of 140GB. Uploaded over 48+ hours, then proceeded to download what was needed. I noted some duplicates where there was a HEIC and JPG version of the same photo, but otherwise the upload went fine, some more guidance on exactly what to expect would have been handy. It now uploads and syncs much faster than it used to (Photo stream)....