My first post on merging iPhoto Libraries was published on January 17th, 2004.
... Using iPhoto Library Manager or similar software, open Secondary Library. Adjust albums so all images appears in EXACTLY one album. (Apple has an AppleScript to find images not in any library, see AppleScript site for iPhoto.)
1b. OPTIONAL. In Secondary Library edit roll names to descriptive names.
2. Burn Secondary Library to iPhoto Disc from iPhoto.
3. Switch iPhoto to Main Library. Insert iPhoto Disc.
4. Expand view of iPhoto Disc. Select ALL albums. Drag and drop on Main Library icon.
Almost 9 years later Apple has posted an officially supported approach to merging iPhoto Libraries - using Aperture.
Nine years ... nine years ...
I could cry.
I did this the hard (hard, hard) way about 6 months ago. I am sure it works a hell of a lot better now. Album Descriptions are still a problem. Both iPhoto Albums and Events can have Descriptions, but only Aperture Events/Projects can have Descriptions. In my testing with iPhoto and Aperture's new unified Photo Library I can edit or create Album Descriptions, but they aren't shown in Aperture.
Maybe this will be fixed in an Aperture update -- but I'm not holding my breath. Apple's description of how they reconciled Aperture and iPhoto doesn't mention this gap (you can submit a request on Apple's Aperture Feedback form). It does list several other issues, these are the ones that seemed significant to me:
- Smart albums from each application are visible and fully functional in the other. However, the album settings must be edited with the application in which you created the album.
- Photos hidden using iPhoto's Hide command cannot be accessed in Aperture.
- PDF files in Aperture libraries are not visible or accessible in iPhoto. (I remember when iPhoto supported PDFs btw)
- If you activate Photo Stream for a library in iPhoto and then open it in Aperture, that library is still linked to Photo Stream. Only one library can be linked to Photo Stream at a time, so if you subsequently open another library and activate Photo Stream, the previous library is no longer linked. (I try to avoid Photo Stream for now - feels like it needs several more iterations)
In keeping with Apple's deplorable documentation policies they omit mention of real issues. Besides the Album Description gap, I would be very careful about using Keywords. Aperture's Keywords use a fairly complex hierarchy model, iPhoto keywords are a flat list; true interoperability is mathematically impossible. On inspection iPhoto only shows the very top of the Aperture Keyword tree; unless you want to go to a flat keyword model don't touch Keywords in iPhoto. Interestingly Smart Albums defined against Aperture Keywords still work in iPhoto even though the Keywords can't be displayed in iPhoto.
Lastly, since the two apps support different numbers of 'Stars' the ratings mapping must be lossy.
I've started cautious use of both iPhoto and Aperture together. I liked iPhoto 9's Event Management tools, and even though they've been dumbed down in iPhoto 11 they're still better than Aperture's. I'd hoped to use iPhoto to export albums to Picasa, but Google stopped support on the Mac Picasa Web Albums exporter and iPhoto PlugIn. It still shows in my iPhoto since it was previously installed, and supposedly it still works if you can find it. (Proof that I am the proverbial dinosaur -- few seem to care that this app was discontinued.)
I'll update this post with what I learn over time.