I take a lot of photos of laptops and other hardware that I review as a freelance tech writer. I also take a lot of photos of things that aren't tech products, and I don't like have to sift through pictures of PCs and printers when I'm browsing my iPhoto library. The solution? Multiple iPhoto libraries.
Dividing your photos among multiple iPhoto libraries is useful if you use your Mac for home and work. It's also useful if your iPhoto library is eating up a large chunk of your hard drive. You can set up additional iPhoto libraries on an external hard drive, though this solution is probably more useful for Mac desktops, where a hard drive is connected or always nearby. For laptops, however, it's a great way to offload some of the seldom viewed or older pictures in your library.
Multiple iPhoto libraries are easy to set up and switch between. Here's how:
To create a second iPhoto library, quit iPhoto and then hold down the Option key while you launch iPhoto. This will open a window that displays a list of your various libraries. Hit the Create New button, give the library a name, and choose a location (including an external hard drive, if you have one connected). Hit save and iPhoto will open your new library.
You'll first need to export photos (File > Export) from your original iPhoto library to your desktop before importing them into your new library. You can choose File > Import to Library to select files to import or you can simply drag files or folders from the desktop to the iPhoto window. You can then move the exported photos to the trash and remove them from your original iPhoto library.
Lastly, there is no way to designate a default iPhoto library. Unless you hit Option when launching iPhoto to choose a library to open, iPhoto will open the last library you used. To switch between libraries, you will need to quit iPhoto, launch iPhoto while pressing Option, and choose a different library to open.
To read how to back up your iPhoto library, or parts of it, click here.