Lightroom Classic CC catalog FAQ

A catalog is a database that tracks the location of your photos and information about them. When you edit photos, rate them, add keywords to them, or do other things to photos in Lightroom, all those changes are stored in the catalog. The photo files themselves are not touched.

Note: Catalogs are different from collections. Collections are an organizational tool within a catalog. See Work with photo collections.

When you start Lightroom the first time, it automatically creates an empty catalog file (for example, Lightroom 5 Catalog.lrcat) for you. To start working with this default, empty catalog, click the Import button.

For more information on catalogs, including a video tutorial, see How Lightroom catalogs work.

• To create a catalog: Start Lightroom and choose File > New Catalog. Specify where you want to store the catalog, enter a name, and click Create.
• To open a different catalog: Choose File > Open Catalog, navigate to the location of the catalog you want to open, and click Open.
• If you have multiple catalogs, tell Lightroom which one to open when you start the program: Choose Edit > Preferences (Windows) or Lightroom > Preferences (Mac OS) and then specify an option in the General panel. For more information on the choices, see Change the default catalog.

When you upgrade to a new version of Lightroom and open a catalog from an older version, Lightroom upgrades the catalog automatically. The old catalog remains untouched. The new, updated catalog contains all of the metadata associated with the previous catalog and photos.

No, the catalogs in Lightroom aren't backward compatible. Catalogs from a new Lightroom version cannot be opened in the older versions. 

When you try to open a catalog from a new version into an older Lightroom version, you get a dialog displaying: The Lightroom catalog named [Your Catalog Name] cannot be opened because it is too new to be used by this version of Lightroom.

To work in the older versions, import the required photos into Lightroom and create another catalog from that version.

Check the table below to know your catalog compatibility.

By default, Lightroom saves catalogs in the following folders:

• Windows: \Users\[user name]\Pictures\Lightroom
• Mac OS: /Users/[user name]/Pictures/Lightroom

For the default locations of catalogs and other important Lightroom files, see:

• Preference and other file locations | Lightroom CC and 6
• Preference and other file locations | Lightroom 5

No, you can't store catalogs on a network but you can store your photos on a network. Smart Previews let you edit your photos in Lightroom even when you are disconnected from the network or when your computer is disconnected from the drive that contains your photos.

You can move your catalog to a different location on your computer's hard drive, to an external disk, or to another computer altogether. Simply use the Explorer (Windows) or Finder (Mac OS) to drag or copy the following files to the new location:

• Catalog: [catalog name].lrcat
• Previews: [catalog name] Previews.lrdata
• Smart Previews (Lightroom 5 and later): [catalog name] Smart Previews.lrdata

You can rename a catalog in the Explorer (Windows) or Finder (Mac OS). If you rename a catalog, make sure to also rename its corresponding Previews and Smart Previews files.

Note: Smart Preview cache files are available for Lightroom 5 and later, not earlier versions.

After you rename your catalog, you might have to help Lightroom find it. See Lightroom can't find my catalog. How do I find it?

You can back up your catalog automatically when you quit Lightroom.

Important: Backing up your catalog does not back up the photos it references. For more information on backing up and restoring catalogs, see Back up a catalog.

Catalog optimization does several things to your catalog:

• It reorganizes the data in the catalog so it can be retrieved faster.
• It updates the database data so the fastest retrieval method can be used.

Using Explorer (Windows) or Finder (Mac OS), locate the folder that contains your catalog. Then, drag the following files to the Recycling Bin (Windows) or Trash (Mac OS):

• Catalog: [catalog name].lrcat
• Previews: [catalog name] Previews.lrdata
• Smart Previews (Lightroom 5 and later): [catalog name] Smart Previews.lrdata

To combine or merge catalogs — or to move photos from one catalog to another — you import one catalog into the other.

The easiest way to use Lightroom on more than one computer is to keep your catalog and photos together on an external drive. Then, in preferences, tell Lightroom to open that catalog by default.

There is no specific maximum number of photos you can store in a Lightroom catalog. If your catalog grows large and you notice Lightroom slowing, see Optimize performance for a whole toolbox of suggestions on how to speed it up.

Lightroom 2 - 5 supports photos up to 65,000 pixels long or wide or up to 512 megapixels, whichever is smaller.

If you move or rename your catalog, you could encounter a "Lightroom catalog was not found" error the next time you open Lightroom.

If you move image files in the Finder (Mac OS) or Explorer (Windows), the Lightroom catalog could lose track of them. When a catalog can't find a photo, a Photo Is Missing icon appears in the photo thumbnail in the Library Grid view and in the Filmstrip. The icon is an exclamation point (). The error "File could not be found" appears over the photo preview in the Develop module.

1. In the Grid view of the Library module, click the Photo Is Missing icon in a photo thumbnail.
   
2. Click the Locate button and navigate to the folder that contains the photo.
3. Click Select.

You can find the contents of missing folders in a similar way: Right-click (Windows) or Control-click (Mac OS) a folder in the Folders panel that has a Question Mark icon () and choose Find Missing Folder. Navigate to the location of the folder and click Choose.