Photo Library 'originals' folder suddenly grown in size

To remove all originals in one go and start over with a small library, you can simply check, if all imported originals have made it to iCloud Photos.

When you are sure, that all photos have been uploaded,

• quit Photos,
• make a backup copy of the current photos Library on an external volume,
• then delete the complete Photos Library.
• launch Photos again, while holding down the options key ⌥ . Select to create a new, empty library.
• Make this new library your System Photos Library and enable again iCloud Photos. Enable "Optimise Mac Storage"
• Now waiting for the photos and albums to reappear. You will get all photos, albums, smart albums, folders back, but your projects will be missing. This is why you need the backup.

Initially your library will be very small, but it will probably grow again, slowly, as your are using photos. Even if you are not using "Download Originals", Photos will try to keep the most recently originals, as space permits. I would not worry too much about it, unless the free storage on your Mac is dropping below 20GB and your Mac gets very slow. Photos should automatically remove originals again, if more free storage is needed, as Tony pointed out.

Hi

Have you been viewing/editing/exporting/sharing any of your photos. Or created slideshows, or other projects?. If so, in order to do this then the original is downloaded. They are removed again when the space is needed.

What size is your library in iCloud. You can generally expect your on mac library to be 10% to 20% of this.

And SERIOUSLY - what are you doing messing around inside your library deleting stuff. It is not just a collection of files, but also a database. The database expects to find the files where it has put them. Manually deleting stuff in there risks damaging your library to the point it will not function - subsequently risking your ability to access your photos via the photos app at all.

OK - that is odd.

The problem is apple doesn't document in detail when/why originals will be downloaded, or when/why they will be removed again. What we are told is they will be removed when the space is needed.

It is possible that they are being downloaded to allow the image scanning (face id, object recognition, live text etc etc) to take place. In which case they might be removed again when that process is complete (thought that may take some time - days/weeks)

So the only suggestion I have is to ignore it. If your drive starts to get full any un-needed originals should be removed.

The library size to expect:

I am trying to purchase all devices with the maximum of available storage, so I do not need to "optimise storage": I like to have all originals stored locally, so Time Machine can back them up, and most important, so I always will have access to my photos, even if the network is slow or down completely.

But the Mac the university gave me to use for lectures to present my slides has only 252GB of storage and I have to use "optimise storage" to access my photos in iCloud. My iCloud Photos Library has a size of 216.8GB.

On the smallest Mac the "originals" folder is nearly empty has just a size of 450MB. The largest entity is the folder resources. It is holding the optimised versions, the edited versions, the thumbnails and previews. The largest items are the edited versions of the externally edited photos, which can be very large, particularly, if the external editors are saving the edited versions back in a lossless format like TIFF. The resources are having a size of 17GB, and there is no way to reduce the size, as long as I am not compressing and reimporting the edited versions.