When you import photos from a different Lightroom catalog into the current catalog, you can specify options to handle new photos and photos that already appear in the current catalog.
Import photos from a different Lightroom catalog
Catalogs from earlier versions of Lightroom, including public beta releases, must be opened and updated before they can be imported into another catalog. See Upgrade a catalog from an earlier version of Lightroom.
Copy New Photos To A New Location And Import
Imports photos to a new location. Click Choose and specify the folder.
Replace metadata, Develop settings, and negative files to override all the settings in the current catalog. If you choose this option, you can select the Preserve Old Settings As A Virtual Copy option to keep a backup. You can also select the Replace Non-Raw Files Only option to avoid replacing raw negatives. If changes to raw negative files affect only metadata, selecting this option helps save time.
Replace metadata and Develop settings only to leave the negative files (the source photos) unchanged. If you choose this option, you can select the Preserve Old Settings As A Virtual Copy option to keep a backup.
Replace nothing to import only new photos.
If photos in the current catalog are missing and can be found in the imported catalog, indicate whether you want to update the metadata and Develop settings for these files. Select the Preserve Old Settings As A Virtual Copy option to keep a backup. If the photos missing in the current catalog appear in the imported catalog, specify whether the missing files are copied and where they copied to.
Import photos from Photoshop Elements
Lightroom detects if your computer has a Photoshop Elements catalog and can import photos and data from the PSE catalog into a new Lightroom catalog. Lightroom imports photos and data from Photoshop Elements 6 through Elements 11 on Windows. Lightroom imports photos and data from Photoshop Elements 9 through 11 on Mac OS.
See Going from Photoshop Elements to Lightroom, a series of three videos on Adobe TV, for tutorials on transitioning from PSE to Lightroom and understanding the differences between the applications.