Is is possible to make an album invisible to the public but visible to registered users?
Yes.
1. in config, make sure 'show private album icon to unlogged user' is set to YES.
2. Now go to the album list, and click on 'properties'.
3. Change the 'Album can be viewed by to 'Registered users'.
4. If you, as admin, want to see the album, you must leave '1' above at YES. If you turn it to NO, unlogged users won't see the icon or album name, but you won't be able to see it yourself (this is to be fixed in next release). You will have to change the setting back to YES to see or edit the album.
I knew about the options in Properties for Albums. The problem I have with them is the album still is not hidden from unregistered users, it is just not accessable to them. What I meant was the album could not be seen unless you were logged in. Any ideas if that is available?
yes, if the 'show private icon' is set at NO. But if you want to see them, you will have to do this fix; http://forum.coppermine-gallery.net/index.php?topic=3238, or wait till the next release.