Shared iCloud Photos Library on Mac with Photos Library on SSD and two users

[acousticbiker]

I’m setting up an M1 iMac for my wife and I as two users and Mac Photos Library on an external SSD. We currently both use my Apple ID to have the same iCloud Photos Library. With the upcoming Shared iCloud Photos Library, we plan to move to using separate Apple IDs and I’m wondering how best to set her up on Photos on the Mac in this scenario.

Right now, I plan to set her up as a user with her own Apple ID but leave Photos syncing off in iCloud and have her use the external SSD Photos Library (which is the one under my Apple ID). When Shared iCloud Photos Library gets released, I’m thinking I should stick with that same approach on the Mac and not turn on Shared iCloud Photos Library because if I did it would then download the thumbnails of our Shared iCloud Photos Library (around 540GB) which would waste space and probably be confusing if she is still accessing the Photos Library on the external SSD.

Does this sound right, am I missing something, or is there a different approach? Would especially appreciate anyone who’s tried Shared iCloud Photos Library with my setup (two users on a Mac using the same Photos Library on an external SSD)

 

[Mike Boreham]

I think you are making it harder than it needs to be! And possibly some misconceptions.

When Shared Library is released, and you have set up a separate ID for your wife, you should turn on iCloud Photos on both your IDs and all devices, create a Shared Library from your ID, and invite her to share. When she has accepted you will then each see, on all your devices, your own Personal Libraries, and the new Shared Library, which will be empty until you move some pics into it. She will only see the photos you add to the shared library, not all 540GB. You can decide what to add. You will also see pics she adds to it of course.

You can set the camera to automatically put all the pictures you each take in the Shared Library (if this is what you want), and is how my wife and I have ours set. By default they go into your Personal Libaries, as do screenshots, and pics saved from FB or WhatsApp.

As I said you each have your own Personal Library as well and it is very easy to move pics between Personal and Shared. So for my wife and I, our Shared Library is all the pics we are both interested in, and our Personal Libraries only have pics not of joint interest. On all devices you can choose very easily to view either Shared or Personal or both and each photo is labelled as being in either Shared or Personal. (You can turn this label off if you want)

Each person can only have one iCloud Photos Library, and it doesn't matter where it is located. On Macs it can be on an external.

Note that photos you each contribute to the Shared Library only appear on the other's devices as separate photos, not in any albums or folders you may each create. In other words you each need to apply your own organisation to the Shared Library on your devices. This was a big disappointment to us as my iCloud Photos Library has 80k pics in 600 albums and folders, and I was hoping to share this with my wife, but 80k photos with no organisation is useless. Many of our pics are scans or have no EXIF so Photos app can't organise them for us. So we are just using it for photos we take going forward. We have both have Lightroom Cloudy on all devices which has the 80k fully organised and functions like the single library you currently have while on the same ID. I was hoping that this new Apple Shared Library would enable us to dump Adobe...it may yet.

It probably sounds more complicated than it is in practice and you will soon get the hang. If you are worried about space on any device turn on optimised in Photos settings on that device.

 

[acousticbiker]

So I just setup the new M1 iMac for my wife and I as separate users and it turns out we can’t both open the same Mac Photos Library on the external SSD. If one person has it open and the other gets an error. Is there a workaround for this?

I would rather not have one of us have to view a Shared iCloud Photos Library since even with ‘Optimized’ (not downloaded) selected, it can still take a lot of memory (for example, on my MacBook Air, my 540GB iCloud Photos Library takes up 170MB in Optimized mode) and our new iMac has 256GB internal.

 

[Mike Boreham]

So I just setup the new M1 iMac for my wife and I as separate users and it turns out we can’t both open the same Mac Photos Library on the external SSD. If one person has it open and the other gets an error. Is there a workaround for this?

I would rather not have one of us have to view a Shared iCloud Photos Library since even with ‘Optimized’ (not downloaded) selected, it can still take a lot of memory (for example, on my MacBook Air, my 540GB iCloud Photos Library takes up 170MB in Optimized mode) and our new iMac has 256GB internal.

No the same actual Library file on an external cannot be opened from two different computers at the same time. The whole basis of iCloud Photos is that each person has their own iCPL, which contains the Shared Library and their own Personal Library. The Shared Library is synchronised between the two of you.

The size of an Optimised Library depends on the amount of free space on the device it is on. You don't say what size the drive is where your 540GB lib uses 170GB optimised, but if you downloaded a 540GB library (with Optimise on) to a 256GB Mac it would not not use 170GB.

 

[acousticbiker]

No the same actual Library file on an external cannot be opened from two different computers at the same time. The whole basis of iCloud Photos is that each person has their own iCPL, which contains the Shared Library and their own Personal Library. The Shared Library is synchronised between the two of you.

If I have Download Originals selected, will it also download the photos in the Shared Library?

You don't say what size the drive is where your 540GB lib uses 170GB optimised

256GB

 

[Mike Boreham]

If I have Download Originals selected, will it also download the photos in the Shared Library?

Yes

256GB

The exact words Apple uses are:

Apple don't say what "low on space" means. As a test I once downloaded my 680GB library onto a test macOS install on a 60GB partition. I didn't note the exact size of the optimised lib but it was small enough to leave reasonable free space (for a 60GB partition).
As you use the library it can grow, as originals are downloaded for editing etc, and free space may shrink for other reasons of course. As free space shrinks, optimisation is supposed to work to restore it but this happened slowly last time I tried this (long time ago may have improved). If you get in this situation you can just delete the Photos lib and let it download a new optimised one appropriate for the free space you have.

 

[acousticbiker]

The exact words Apple uses are:
View attachment 2091891
Apple don't say what "low on space" means. As a test I once downloaded my 680GB library onto a test macOS install on a 60GB partition. I didn't note the exact size of the optimised lib but it was small enough to leave reasonable free space (for a 60GB partition).
As you use the library it can grow, as originals are downloaded for editing etc, and free space may shrink for other reasons of course. As free space shrinks, optimisation is supposed to work to restore it but this happened slowly last time I tried this (long time ago may have improved). If you get in this situation you can just delete the Photos lib and let it download a new optimised one appropriate for the free space you have.

Yeah, I had a previous 256GB MBA that let it grow until it even gave me low memory warnings (less than 10GB remaining). Didn’t think of deleting the library and letting it “re-optimize”