Is it necessary to have full copies of pictures on my MacBook Air for offline editing?

Hold it! I think I'm wrong. It looks like printing doesn't load full sized images! Editing does. So it looks like you have to select the images you will want to edit, and then go though them and, one at a time, hit return to go into edit mode, wait for the little circle in the lower right corner to fill, and then go to the next one, wait, etc.

The best deal will be to have switched to "Download Originals" before starting this edit loading journey, in order to insure that the full files are retained.

markwmsn wrote: Of course, if MMuddler's MacBook Air had enough disk space to support "Download Originals", the download question need not arise in the first place.

I was thinking (but not saying, for some reason) of setting "Download Originals" so the recently downloaded files wouldn't get zapped to save storage. When he gets on the plane, no more downloads will occur, anyway, and he can reset to "Optimize" for when he connects back to the internet.

I'm not sure exactly what happens if you switch from "Optimize" to "Download" and the drive fills up. I bet things get very slow.

MMuddler wrote: Do I have to make sure my MB Air has full copies of pictures I want to edit while on the airplane since I will not be able to download while seeking to edit in Photos?

That's best. Relatively quick way to ensure that you have full sized images is to select the ones you want to work with and print them, ⌘-P. Photos grabs the full sized image from iCloud in order to print. But don't print them to paper! Print them to PDF!

You'll make a pretty big pdf file that has all those pictures in it, but it won't use any paper, and it will force the download of the full images. You can, of course, trash the pdf file afterward.

"The best deal will be to have switched to "Download Originals" before starting this edit loading journey, in order to insure that the full files are retained."

Of course, if MMuddler's MacBook Air had enough disk space to support "Download Originals", the download question need not arise in the first place.

markwmsn wrote: .. If you try to switch from "Optimize" to "Download" when the drive doesn't have enough room, the change may well be denied.

Good point-- Photos tries to calculate how much room it will take before it gets bogged down.

I had thought you could do the one-by-one Edit mode procedure, and then just turn off the internet. But it seems like you'd want to use the internet while waiting in the airport.

You could do the one-by-one Edit mode procedure, and then those pictures with "Export Unmodified Originals" to be sure you had the original files before takeoff. Then re-load one if it won't edit.

Buy yourself a 2TB SSD and back all you photos up to that and keep them off you Mac until you want to edit them

If you try to switch from "Optimize" to "Download" when the drive doesn't have enough room, the change may well be denied.