Guest Photo & Post By Nat Coalson

Part 1 – About Lightroom Catalogs

During the past year alone, I’ve taught nearly two dozen classes and workshops on Adobe Lightroom, and several aspects of using this essential software keeps rising to the top as significant hurdles for new users. In this two part mini-series, I’ll explain the fundamentals of getting photos into a Lightroom catalog and how Lightroom uses the catalog to manage your files.

First point: you need to Import photos into Lightroom in order to work with them. Until you do an Import, Lightroom doesn’t know anything about the files on your hard drive, and they won’t show anywhere within the Lightroom window.

Unlike Adobe Bridge, which is a simple file browser, Lightroom uses a database to manage and track all your work with photos. This database is called the Lightroom Catalog, and it’s a file stored on your hard drive. (The default location of the Lightroom catalog is in your Pictures folder.)

The Import process creates new database records within the catalog. These records include information about the file name, location and other aspects of the original files on your hard drive. The actual image files are never stored within the catalog! The catalog works with the files by reference, meaning that the files always need to be available to Lightroom in order to work with them.

For example, if you import files from an external hard drive, and later have that hard drive turned off or disconnected from the computer, Lightroom won’t be able to find the files. Similarly, if you Import files into Lightroom and then later move or rename those files using the Mac Finder or Windows Explorer, Lightroom again won’t be able to find the files.

In the above cases, you’ll end up with question marks showing on the folders (in the Folders panel) and/or on the photo thumbnails in the Library views. A question mark means that Lightroom doesn’t know where the photo is. And the only reason this occurs is if the photo isn’t where it was when it was imported, or it’s not using the same name. (You can relink missing photos, which I will cover in a future article.)

So the key points to take away from this article are 1) the Lightroom catalog is a database containing information about the photos you’ve imported, but not the photos themselves, and 2) you always need to have the original image files available to Lightroom in order to process them.

In the next part I’ll explain how to import photos and how to properly reorganize your photos on the hard drive. Stay tuned!

Nat Coalson is the author of Nature Photography Photo Workshop and  Lightroom 3: Streamlining Your Digital Photography Process