How does Lightroom confirm an image is already in its' database?

[kathya]

Lightroom Version Number

8.0

Operating System

1. Windows 11

I am uploading some photos that I'm 99% sure I've uploaded before but LR complains that the images are new. I am wondering how Lightroom determines duplicates?

 

[clee01l]

Assuming you have "do not import Suspected Duplicates". checked in the import dialog, There are several factors, beginning with file name, file size, Capture Date and then other factors. If you suspect duplicates, go ahead and import then search beginning with file name and capture date. If you use a date named folder scheme, you are unlikely to encounter duplicates because the File system won't put two files with the same name in the same folder.

 

[Paul McFarlane]

If you use a date named folder scheme, you are unlikely to encounter duplicates because the File system won't put two files with the same name in the same folder.

That's true of Lightroom Classic, but doesn't apply here (this is Desktop).

Lr calculates the file’s checksum (hash) to ensure it’s an exact duplicate. It won’t identify duplicates that are edited copies of an existing photo or if another program has changed the metadata in the file.

 

[clee01l]

That's true of Lightroom Classic, but doesn't apply here (this is Desktop).

Ah! I missed that. The my initial response probably does not apply. In Lr there is no option to "do not import Suspected Duplicates". And since there is no rename on Import option the original file name can be used by the Op to determine If Lr did for some reason import a duplicate.