HOWTO to delete files from my iCloud Photo Library WITHOUT deleting them from my Mac

so I don't have iCloud Photo Library enabled on my Mac.

Providing that's correct, just go to iCloud.com> Photos via your computers web browser and delete them from there.

I think I have the same issue, but would phrase it differently: I would like to enable iCloud Photo Library, but only for certain albums. Similar to the Contacts paradigm, it would seem there should be an On My Mac section and an iCloud section, to provide control over which albums/photos get uploaded. Is there such control, and if so, how?

The previous response seemed to say to let them all upload and then delete the ones you don't want in the cloud through the browser. But, wouldn't this delete action sync down to my Mac and delete there? And, even if it didn't, it seems quite a roundabout and inefficient way to attain the desired result.

I would like to enable iCloud Photo Library, but only for certain albums. Similar to the Contacts paradigm, it would seem there should be an On My Mac section and an iCloud section, to provide control over which albums/photos get uploaded. Is there such control, and if so, how?

You can do that by having more than one Photos Library, one with your iCloud photos, and one library with photos that are only stored locally.

See "Use multiple libraries in Photos": https://help.apple.com/photos/mac/1.0/?lang=en#/pht6d60b524

Wow, thanx, I guess. I tried to create another library and switch system libraries and it started downloading everything from the cloud to the new system library, which was exactly what I didn't want so I killed that and a big mess ensued. I dragged my new library to the trash and turned off iCloud from my single remaining library, which I restored as "system" and now I have photos both where I want (on my Mac), but also on iCloud, and I don't see how to delete them. Also, the linked help file said to hold down the Option key when I launch, but that only seems to work intermittently! Half the time it just opens a library without letting me know which one! (Can you feel my frustration?) Anyway, several questions, if I may:

1. Why, when I launched while holding down the Option key and while I had two Photos libraries (plus my old iPhoto library), did it not ask me which one? I tried both Option-clicking the Photos icon in the Dock and Option-double-clicking the Photos icon in the Applications folder.

2. With iCloud Photo Library de-selected and with photos both in the cloud and in my library file, how do I delete the whole mess from the cloud? There are over 2000 photos dispersed across 50 albums. I've been able to delete photos from an album, but the empty album remains. I guess the help file couldn't imagine wanting to actually delete an album.

(Also looking for some sympathy.) —Ken

Well, I figured out the answer to the 2nd question: Go to System Preferences > iCloud > Manage… > Photo Library > (something like) Disable and Delete.

Still curious why option-launching Photos doesn't work consistently.