Was recently asked by a small office client to determine the feasibility of sharing a single Adobe Lightroom 4 catalog among multiple users. My client runs a photography studio and employs two part-time assistants. His office equipment consists of four Snow Leopard Macs connected on a LAN using wifi and gigabit Ethernet. Below is a summary of my findings.
Not owning a copy of Lightroom 4, I downloaded and installed the trial version from Adobe’s website. After launching the program, I opened Finder and immediately noticed that Lightroom locks the catalog file that prevents others from opening it at the same time.
However, that wasn’t the only show-stopper. As shown by the screenshot below, Lightroom users cannot open a catalog file that’s located on a removable storage device (external hard drive) or network volume.
The catalog file can only be opened from the local machine where Lightroom is installed. What this means is that if your Mac maintains the master copy of your Lightroom database and other staff members want to open the same catalog, they are prevented by the software from doing so, unless they copy the unlocked file (that includes your changes) to their computers.
This Adobe Forum post describes the fundamental issue: Lightroom is designed as a single user application that doesn’t allow multiple writes to the same catalog using different computers. If two people edit the same image and then export the catalog from their computers, they will generate two catalogs that contain different settings. They will not be able to merge the edits automatically. Importing will overwrite one of the edits.
One idea that I came up with is to set up a quasi-server arrangement, where Lightroom is installed on one machine and each user is given authorization to remotely log into the application from their individual Macs. Screen sharing is a feature that is built into both Snow Leopard and Lion and is simple to set up. The restriction, of course, is that only one user can be logged into Lightroom at any given time. The type of network (e.g., Ethernet, wifi, or VPN) used to access the Lightroom “file server” and the amount of data being passed back and forth are important factors that must be considered in determining the long-term feasibility of this configuration.