how to transfer photos from iPhoto to an external hard drive

- You can not transfer "some of" your iphoto library without iPhoto Library Manager - http://www.fatcatsoftware.com/iplm/ -

- you can transfer some of your photos by exporting - Exporting From iPhoto

- you can transfer the entire iphoto library - -

Moving the iPhoto library is safe and simple - quit iPhoto and drag the iPhoto library intact as a single entity to the external drive - depress the option key and launch iPhoto using the "select library" option to point to the new location on the external drive - fully test it and then trash the old library on the internal drive (test one more time prior to emptying the trash)

And be sure that the External drive is formatted Mac OS extended (journaled) (iPhoto does not work with drives with other formats) and that it is always available prior to launching iPhoto

And backup soon and often - having your iPhoto library on an external drive is not a backup and if you are using Time Machine you need to check and be sure that TM is backing up your external drive

- and using iPhoto Library Manager - http://www.fatcatsoftware.com/iplm/ - you can transfer selected photos between libraries

LN

1, Read Finding the OS X version and build information on your Mac - Apple Support

2, The iPhoto library is a database. Splitting it up into multiple libraries is a non-trival task. You will need some third party software such as iPhoto Library Manager available at http://www.fatcatsoftware.com/iplm/

Make sure the drive is formatted Mac OS Extended (Journaled)

1. Quit iPhoto

2. Copy the iPhoto Library from your Pictures Folder to the External Disk.

Now you have two full versions of the Library.

3. On the Internal library, trash the Events you don't want there

Now you have a full copy of the Library on the External and a smaller subset on the Internal

Some Notes:

As a general rule: when deleting photos do them in batches of about 100 at a time. iPhoto can baulk at trashing large numbers at one go.

You can choose which Library to open: Hold down the option (or alt) key key and launch iPhoto. From the resulting menu select 'Choose Library'

You can keep the Library on the external updated with new imports using iPhoto Library Manager