Like many other users, at some point I asked myself if it was better to have all my pictures in a single catalog or use, for instance, one for my personal pictures and another for work-related ones.
I consider the following points are important when making a decision:
- Order: For each catalog, multiple files and folders are created, for the catalog itself as well as previews and user-created presets. You’ll also need to remember which pictures are imported in which catalog.
- Searches: Obviously, having a single catalog allows you to search and apply filters to all of your pictures, which is far easier and practical than making those searches in multiples places. Simply going from one catalog to another, depending on what pictures you want to work on, may quickly become a hassle. One should take into consideration that it is not possible to have multiple catalogs open at once.
- Presets: They allow saving a lot of time with repetitive tasks, but they belong to the catalog they were created in. It’s possible to transfer them if necessary, but then your work becomes less efficient.
- Synchronization of the metadata and develop settings: In a single catalog, you can easily synchronize o copy/paste the settings to other pictures. You can’t do it between catalogs unless you use presets.
- Backups: It is always very important to back up your data, but it is particularly so in the case of the Lightroom catalog, since it contains absolutely all of the changes you make to your pictures. The original pictures can only be modified by Lightroom if you save the metadata changes, but they are kept intact when you make changes in the develop module. Thus, losing the catalog implies losing all of those modifications. Having multiple catalogs requires you to keep backup files of all of them, including the presets folders.
I realize that some of those reasons are not valid ones for everybody. For instance, the risk of losing data is not greater if you set up an automatic backup system; in this case, you basically don’t need to do anything once that system is up and running. You could also argue that it’s better to keep some pictures in their own catalog, but keep in mind that you can also have that kind of separation in a single catalog by creating distinct root folders for each set of pictures (work-related and personal, by customer, etc…).
Taking everything into account, I think that in most cases, having a single catalog is the way to go, since it offers mainly advantages, as long as you keep your pictures organized. And you can save a lot of time by having access to your pictures and presets in a single place.
The only exception I can think where it might be convenient to use multiple catalogs is for confidentiality or privacy, on specific project in which many people work on the same Lightroom catalog.
Lastly, I want to mention that it is possible to export a selection of pictures as a catalog and also to combine multiple catalogs into a single one. This offers more flexibility and the ability to change at any time how your pictures are organized.