Today’s Question: If I use an external disk [when traveling] for my primary photo files (with a second external disc for backup), should the catalog be also placed on the primary external disk? That would save a step when merging to the home (main) computer, and keep it all together. My laptop has limited storage.
Tim’s Quick Answer: The answer here depends on your priorities. Having the catalog on an external hard drive along with your photos is very convenient when it comes time to transferring the photos to your “master” catalog. However, this approach will also generally have a bit of a negative impact on overall performance in Lightroom.
More Detail: Lightroom makes extensive use of the catalog files, which contain the information about all of the photos being managed by Lightroom. Therefore, having that catalog on a hard drive that provides the best performance possible. In most cases, that translates to having the Lightroom catalog files stored on an internal hard drive.
Of course, it is relatively common that a laptop computer won’t have adequate internal storage for all of the photos you might capture during a trip. In that case, an external hard drive provides an excellent solution for photo storage. In other words, you will have the catalog on your internal hard drive and your photos on an external hard drive. This provides the additional benefit of being able to review your photos (and update metadata for them) within Lightroom even if the external hard drive with your photos is not connected to the computer.
That said, if you have the catalog on the internal hard drive and the photos on the external hard drive, you will likely want to copy the catalog files to the external hard drive in order to have the catalog and photos available on your primary hard drive for purposes of merging your traveling catalog with your master catalog.
In this situation you could simply copy the folder containing your traveling catalog onto the external hard drive that contains your photos, and then import from that catalog on your primary computer. You could also make use of the “Export as Catalog” command (found on the File menu) to help ensure you are copying all necessary files to an external hard drive that can then be connected to your primary computer.
There are obviously a variety of ways you could approach this workflow. You can see my personal approach in the courses “Tim’s Real Organizational Workflow” in the GreyLearning video training library (http://www.greylearning.com). The key is to develop a workflow that makes sense based on your specific needs, and then use that workflow consistently.