Where Aperture stores your managed files in the library
You can always view and work with your photos within the Aperture application. However, you may wonder where your managed image files physically reside in the Aperture library on the computer’s hard disk. By default, your photos are stored in the Aperture Library file within the Pictures folder. For more information about managed image files, see What are managed images and referenced images?.
You can open and see the contents of the Aperture Library file in the Finder by Control-clicking the file and choosing Show Package Contents from the shortcut menu. However, it’s not recommended that you access or work with your originals in this way because you risk interfering with the Aperture library.
WARNING: You should always back up and work with your managed images and projects from within the Aperture application. If you move or accidentally change the files stored in the Aperture Library file, Aperture may not be able to locate your projects and the media they contain. Making a change to a managed file in the Finder, such as renaming it, creates changes that Aperture cannot track.