If you have a MacBook Air with a 128-gigabyte hard drive and have realised that it is fast filling up with high-resolution picture albums in the Photos app. If you don’t want to use iCloud and don’t want to store your pictures online. Here is how you can copy them to an external drive without messing up the Photos app?
Apple’s Photos app lets you create multiple photo libraries within the program, and even store those libraries on external drives. You can reclaim a chunk of your laptop’s drive space by moving your picture library to a new external drive (and deleting it from its original location), but this means you do need to have the external drive connected to the computer when you want to see, edit or share the pictures.
If you prefer to keep your pictures on the ground and out of the cloud, start by getting an external hard drive large enough to hold your growing image library for the foreseeable future. Connect the new drive and quit the Photos program before you copy the library.
Next, go to your Mac’s Home folder and open the Pictures folder. Drag the PhotosLibrary.photoslibrary file to the new drive’s desktop icon (or onto its icon in the window’s sidebar). If you hold down the Command key while you drag the library file, the Mac will copy it to the new location and then delete the file from its original spot, but you might want to make sure everything is copied properly to the new drive first — and then delete the old library file manually.
To point the program to the library’s new location, hold down the Mac’s Option key and click the Photos app icon in the desktop dock to start it up. As the Photos program starts, the Choose Library box appears. Click the Other Library button, navigate to the external hard drive that now houses your library file, select it and click Open. The Photos app should now display your relocated picture collection.