The Mac’s Photos app can take up a lot of storage space—actually, it’s not the app itself that uses up space, but its database of images that you have imported into Photos. So naturally, when you need to free up storage space, one way to do that is to delete photos from the Photos app.
Say you deleted some photos in Photos, but now you need to get those photos back. And what if, after deleting those photos, you added some new ones. So now you want to restore the deleted photos, while at the same time, preserve the just added ones. Can it be done?
Yes, but it requires a little finesse. You will also need an external drive with enough storage to restore your entire Photos Library.
If you have been performing a Time Machine backup, that could help. Here’s the primary concern: Time Machine automatically deletes older snapshots as it adds new ones. Files that have been deleted from your Mac are only retained as long as the oldest snapshot that contained them.
Time Machine retains weekly snapshots until a drive becomes too full to keep the oldest ones. If you have a very large drive or haven’t performed any Time Machine updates in the months since you last had access to the drive, the old Photos Library’s state should be preserved.
Assuming that’s the case, we can proceed.
Apple treats the Photos Library (located in the Pictures folder) as an integral thing: it has a single icon and you interact with it like a file. However, it contains lots of pieces, including the original versions of every imported image and video, thumbnails, an organizational database, and files that represent modifications you’ve made to images. I typically recommend not mucking around inside that package unless you have a corrupted and unrecoverable Photos Library.
Time Machine lets you peer within the Photos Library to retrieve specific images, but I would suggest the best course of action with the highest chance of success is to retrieve the entire archived library. That requires enough storage space, of course, either on the startup volume, the Time Machine volume, or another external drive that can be plugged in at the same time as the Time Machine backup. You best bet is to use an external drive.
Here’s how to restore an entire Photos Library.
Launch Time Machine, which is in your Applications folder. If Time Machine appears in your menu bar, select its icon and click on Enter Time Machine.
Navigate to your home directory’s Pictures folder.
Navigate back in time to when you know the Photos Library was at the state you need.
Control-click the Photos Library to choose Restore “Photos Library,” and then select a destination other than where the current Photos Library lives.
When the restore is complete, hold down the Option key and launch Photos.
When prompted, click Other Library and choose the restored Photos Library.
You can now select and export items from that restored library, and then quit and relaunch Photos with the Option key held to select your startup library, and import those images.
Another option after restoring is to instead use PowerPhotos ($30), which lets you merge Photos libraries. In this case, I recommend stripping all the photos from the older library that you don’t want so you can merge the slimmed-down library with your existing one-you don’t lose metadata, original images and modifications, and other data and changes that way.
Hold down the Option key and launch Photos.
Click Other Library and select your restored library.
Delete everything you don’t want to merge with the new library.
Launch PowerPhotos and use its option to merge two libraries: your now reduced-sized old library and the current active Photos Library.
Another strategy for the future is to maintain separate Photo Library packages if you don’t have enough storage to keep everything in a single library, and want to be sure you don’t lose images or videos you would otherwise have to delete.
This Mac 911 article is in response to a question submitted by Macworld reader Michael.