Can different users on the sam Mac share a photo library?

Where is your Photos Library stored?

Your wife should be able to share it, if the library is on an external drive, with the "Ignore Ownership" flag set, just like it has been recommended for iPhoto.

See this link: iPhoto: Sharing libraries among multiple users

But you will not be able to share the iCloud Photo Library this way.

Best way is iCloud Photo Library - then all of your Macs and IOS devices can share the same library

Otherwise it has to be on an EHD with ownership ignored

LN

Best way is iCloud Photo Library - then all of your Macs and IOS devices can share the same library

Only this requires that both users will have to share an iCloud account and trust each other with a common iCloud password. Using the same iCloud Photo Library on all devices with also result in sharing the iCloud Mail, iCloud Contacts, iCloud Calendar, Bookmarks.

Unless one of the two will only use the web interface. But it still would require to trust the second person with the iCloud password.

We could do a TV show - Do you trust your wife?

OMG not another reality show. 😢

We could do a TV show - Do you trust your wife?

Sure we do. But would you want to have all bookmarks, contacts, calendar entries of your spouse messing up your own lists on you iPad?

Yes - that is exactly how we operate - it works well for us

Don't you trust your (spouse/significant other/partner/misc)?

LN

Don't intend to put it on to an EHD as I back up using an Apple Time Capsule and would prefer not to save to s source that may lose all my photos

If you use a separate EHD to house your library it will also be backed up with Time Machine and you won't be putting it at risk. I have 2 EHDs that are backed up with my TM along with my boot drive.

As far as trusting wives that's not the issue. It's having to put up with going thru all of her emails and messages from her friends to get to my emails and messages. Also I get so many email from the ASC forums that she wouldn't want to do the same.

the library is on the iMac's internal drive under "User > Shared" so we can both access it.

However, it would appear that we both can't.

Sharing a library in a Shared folder stopped working with iPhoto '11. It does not suffice to have read/write access to the folder. As soon as someone writes to the library, this will add items to the photo library with different ownership settings. And you will continually have to repair the photo library before your spouse can access it. To share the library it needs to be on a separate drive or partition where the ignore ownership flag can be set. Only that will work.

Apple explained this here for iPhoto, the same goes for Aperture or Photos: iPhoto: Sharing libraries among multiple users