Q: Merge IPhoto and Aperture Libraries into Photos Library so I can see all albums at once?
I want to be able to view my old photos from Aperture and I Photo along with my new photos without restarting Photos. How do I merge these libraries into one?
Do it using either iPhoto Library Manager or Aperture - once you convert to Photos you can not merge libraries except uploading all to iCloud Photo Library
For multiple Photos libraries Power Photos lets you view them and is a great tool