Today’s Question: I have two folders that have some of the same photos in Lightroom Classic. Is there an easy way to identify the duplicates so I can remove them from one of the files?
Tim’s Quick Answer: In my view the only real option that can be trusted for identifying duplicates is to browse the full group of photos at the same time, sort by capture time (and possibly filter the images), and then review the images to confirm which are duplicates. You can then compare the duplicate images to identify which should be kept and which should be discarded.
More Detail: Unfortunately, there isn’t a reliable and automatic method for removing duplicates in this context. There are a couple of plug-ins that purport to do this, but they only mark suspected duplicates and don’t have good algorithms for figuring out which of the duplicates is the better version to keep, for example.
Therefore, I would suggest browsing both folders and reviewing the images manually.
Start by selecting one folder in the Folders list on the left panel in the Library module and then hold the Command key on Macintosh or the Ctrl key on Windows while clicking on the other folder. In the grid view make sure the sort order is set to Capture Time. This will provide a great starting point for identifying duplicates, because duplicate images will be next to each other, assuming the capture time hadn’t ever been modified for the images being reviewed.
Of course, just because the thumbnail is the same doesn’t mean you can be certain that one of the apparent duplicates needs to be deleted. For example, you might have an original raw capture as well as a virtual copy or perhaps a TIFF or PSD file that was created via Photoshop. However, you can review the file types in this context to get a sense of whether there is a duplicate that should be deleted.
If you have true duplicates, such as two raw captures that are obviously the same image in different folders, the next step is to decide if one should be prioritized over the other. For example, you can review whether one or the other was optimized in the Develop module or had specific metadata updates such as star ratings or keywords. If there is one clear “winner”, the other image can be deleted. If there have been updates to both, you may want to apply metadata updates across the two images to get one of them updated with the most (and most recent) info.
Ultimately this process can be a bit time-consuming, but in my view it is important to be sure you’re deleting the right duplicate to avoid losing metadata updates or other important changes. In the future, hopefully there will be more powerful tools for reliably determining which images can truly be deleted as duplicates in Lightroom Classic without as much effort.
