Q: how do i back up photo albums

Your pictures will stay in albums

and backing up is the same as it always have been - do it regularly - TimeMachine is a good option for one backup hourly

LN

I'm still not clear what you want

If you have an external hard drive that is formatted Mac OS extended (journaled), is not used as a TimeMachine backup volume, is connected with a fast wired connection and is always  available prior to Photos being launch then you can move your library to it and run it there - quit Photos and drag the library to the EHD and double click on it to open it there - this is not a backup and you have to have a backup just like you alwys do

If you want Photos in folders matching the Photos albums on an EHD then you open each album, select all and export to a folder on the EHD naming it the same as the album - the is a backup of the photos with their selected metadata - it is not a bakcup of yoru Photos library

If you want something else you need to clearly state wha you want to accomplish

LN

Use this AppleScript to export those albums to folders on the hard drive with the same name as the album: Export Albums to Folders - Jacques Rioux's Script.  You can download a compiled version of the script as an application from this tutorial site: P01 - Applescripts from Photos’ User Tips Compiled as Applications.

Then copy the folders to a external HD for backup.  When the copying has been completed and confirmed was a good copy, you can delete the folders from your internal HD.

You are welcome - I think

Post back if you need more

LN