Today’s Question: I am doing as I saw you suggested [putting the catalog on an external hard drive] to be able to use Lightroom Classic on both my Mac and PC. I formatted my drives in exFAT and they are read fine by both computers. My problem is that for some reason Lightroom Classic is not able to find most of my photos. If I locate them and restart, they are found, but the next time I use Lightroom they are again lost. What do you think I am doing wrong?
Tim’s Quick Answer: This issue is caused by the fact that Windows and Macintosh use a different approach to managing the path to folders and photos. In this scenario I recommend using a top-level folder for photo storage so you only need to reconnect that single folder when you switch platforms.
More Detail: The Lightroom Classic catalog is cross-compatible with both Windows and Macintosh, meaning you can open the same catalog on computers running either Windows or Macintosh (though you can still only open the catalog on one computer at a time).
The first step is to make sure the external hard drive you’ll use to store the catalog is formatted with a file system that is compatible with both Windows and Macintosh. For example, you can format the drive with the exFAT file system, but keep in mind that formatting a drive will completely erase the contents, so you’ll want to perform this step before you have put any data on the drive.
I then recommend creating a top-level folder on the drive for storing your photos. For example, you could create a “My Photos” folder on the external drive, and then create subfolders that will contain your photos within that top-level folder. Photos contained within that top-level folder can then be fully managed within your workflow using Lightroom Classic.
When you switch platforms, all folders and photos will appear missing initially. That’s because Windows is using a drive letter to track the hard drive, and Macintosh is using a volume label. After switching platforms and opening the catalog, you can then right-click on your top-level folder in the Folders list on the left panel in the Library module and choose “Find Missing Folder” from the popup menu. Navigate to that folder on the external hard drive and click the Choose button, and all folders and photos will be reconnected, so they are no longer missing.
I also recommend assigning a specific drive letter to the external hard drive on Windows using the Disk Management feature, so that when the drive is connected it will always be assigned the same drive letter.
You will need to use the “Find Missing Folder” feature each time you open the catalog on a different operating system, assuming you had reconnected the folders and photos the previous time you were using the catalog on a different operating system. But it is possible to work with the same Lightroom Classic catalog on both Windows and Macintosh, as long as you don’t mind reconnecting the top-level folder each time.
