iPhoto backup and external storage
I have run out of disc space on my macbook. It is full of photos. Everything is backed up with time machine, but I am going to buy another external HD to store all the old photos. I know I can just copy the whole iPhoto library to the HD, but is there a better way? Perhaps an app that will allow my to incrementally add any new photos, but not try to be an exact copy of the macbook (which will have the older photos deleted). Or should I just start to use iPhoto from an externally stored library (this makes me nervous, and obviously I will need to change Time Machine settings). What is the best system? Many thanks.
iPhoto '11, Mac OS X (10.6.8)