Make Time Machine-like backups of Photos onto external drive I don't need to backup my whole disk but I want to backup my Photos once a month. From what I've read, Time Machine seems to work amazingly well so I was hoping for a similar solution for Photos.

I want to be able to delete the Photos library on my internal drive but keep the files "alive" on an external one. I use the "new" photos app introduced like half a year ago and migrated my library back then accordingly.

It would be perfect if I could do that with 2 separate external drives.

Is there any software that gets this job done? Maybe even something from Apple? Most stuff I find wants you to backup to iCloud or doesn't really go with the user deleting the files off his internal drive.

Thanks in advance.

EDIT: El Capitan, MacBook Air 2013, the external drives both are NTFS but I would also accept reformatting them if that was necessary. I use 3rd party drivers for NTFS access which work fine for me.
You will need an external drive formatted Mac OS Extended (Journaled) to use as a Time Machine backup. TM cannot use a NTFS formatted disk as the backup destination.

Unfortunately, Time Machine cannot use an NTFS drive as a backup source, either. Time Machine relies on the Mac OS Extended (Journaled) file system on all drives acted on to do its work. (This isn't strictly true as you can create and backup to sparsebundle files on a network drive mounted with NTFS, but this is not in the scope of your question.)

Thus you need two Mac OS Extended (Journaled) external drives - one for the TM backup; one for the Photos Library. If you know how to use Time Machine, you can stop reading. If not, keep going.

In System Preferences > Time Machine, Click the Select Disk... button and choose this external disk for Time Machine backups. One the disk is selected, click the Options... button at the lower right, which brings up the window where you can exclude items from backups. Normally, all connected disks (internal &amp; external) are backed up, except for the Time Machine disk. You can drag (or click the + sign) and add Macintosh HD (or whatever else you may have named the boot HD) to the list of excluded items. This will enable you to backup only the external HD with the Photos library.