Before you recover your photos from the Time Machine backup, you need to know that your photos are stored in a file called Photos Library.photoslibrary. So you should select this file in your Time Machine backup rather than the Photos app.
Here are the steps to recover photos from the Time Machine backup.
- Quit the Photos app.
- Go to Launchpad > Other > Time Machine and double-click to open it. And you will see your available backups.
- Click the date of your last backup, navigate to the backup of your photo library, and then click to select it.
- Click Restore.
Once it has been done, press the Option key and click the Photos app to open, and you will be given a choice of the old or new photo library.
If you still can't recover your photos from the Time Machine backup, you can use third-party software like iBoysoft Data Recovery for Mac, which can help you recover various files from your Mac running macOS or Mac OS X securely and effortlessly.