Populating the Zope object database with lots of digital photos is not such a great idéa. ATMediaBundle seems promising.
Right now I'm trying out ATPhoto, ATPhotoAlbum and FileSystemStorage that comes bundled with ATMediaBundle for Plone, and I've managed to get ATPhoto to use the filesystem as a backend. It was actually as simple as changing the file system storage in config.py of ATPhoto to FileSystemStorage and then configure the filesystem save path for FileSystemStorage in the Plone settings page.
ATMediaBundle is alpha, so it's not ready for prime time they say, but why not take it for a test ride? It's very prommising and needed indeed.