Today’s Question: Is there any difference (effective or otherwise) between: (1) creating a backup via “Export as Catalog” and (2) copying both the catalog and photograph files outside of Lightroom?
Tim’s Quick Answer: The only difference relates to the process itself, with the net result being the same provided you copy or export all photos and the related catalog files. This assumes, of course, that you ensure that you are copying the same photos (presumably all of them) and that you copy all files related to your Lightroom catalog.
More Detail: The only real issue here is to make sure that you are copying all photos and the full set of catalog files. Both approaches involve a slight risk of “user error”, and thus I encourage taking a methodical approach.
Exporting as a catalog ensures you are copying the full catalog along with the photos. This is the approach I generally recommend for backing up “everything” related to your photos. The key is to make sure you are actually exporting all photos within the catalog when you use this process.
To be sure you export all photos, start by choosing the “All Photographs” option in the Catalog section of the left panel in the Library module. Then make sure no filters are enabled, so all images in the catalog are actually available for selection. Then choose Edit > Select All from the menu to select all of the images, and then choose File > Export As Catalog from the menu. You can then specify where you want to copy the catalog and photos, making sure to turn on the “Export negative files” so that the photos themselves are copied as part of this process.
While you need to exercise a degree of caution when using the “Export as Catalog” option, in my mind there is even more risk of making a mistake when taking a “manual” approach to copying the catalog and your photos. To begin with, the catalog files and your photos might be stored in different locations. And, of course, there are other potential issues involved as well. But provided you copy all of the files associated with your Lightroom catalog and all of the photos referenced by your Lightroom catalog, the net result will be the same as using the “Export as Catalog” command.