Today’s Question: When I removed my hard drive from the laptop, the photos in Lightroom showed as “this file is missing”. Is this correct? Should the original source remain plugged in order to work in Lightroom? I do understand that I won’t be working on the original photo.
Tim’s Quick Answer: When the source images are not available on the computer you’re using for Lightroom, the images will indeed show as “missing”. There is no need to be alarmed, provided you know that the photos are only missing because your hard drive is disconnected. And even while the drive is disconnected, you can still update metadata and perform certain other tasks based on the Lightroom catalog.
More Detail: Because Lightroom employs a catalog to maintain information about your photos, you can work with your photos to some extent even when the source images are not available. For example, you can still view thumbnails and previews of your photos, because Lightroom generates those images for reference and maintains them with the catalog rather than with the source photos.
You can also update metadata, such as assigning star ratings, adding keywords, and other details, since that information is written to the catalog as well. If you generate Smart Previews for your photos you can even work in the Develop module and even export copies of your photos based on Smart Previews, all while the source files are unavailable due to the disconnected hard drive.
So, while there are situations where you need to have the source photos available to Lightroom, you can also perform a wide variety of tasks even when you have disconnected an external hard drive that contains your photos. This is one of the benefits of using Lightroom to manage your photos, as opposed to other software tools that do not employ a catalog.