Lightroom Don't Import Duplicate Algorithm seems flawed.

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  • Updated 5 years ago
here is what i have in the 'source' folder:

1. 2012-09_22605-05140 [NIKON D700] (already imported in the catalog)
2. 2012-09_22605-05140 [NIKON D700

Now, the first file has already been imported. In the second round, when I point my LR to the same source folder, LR says the first file is duplicate, but not the second one. The second one differs from the first only in the file name. Notice the missing ']' character at the end of the file name.

So what you are saying is this:

if filename equals "existing" AND date/time equals "existing" AND file size equals "existing" THEN its a match.


If yes, it still defeats the purpose of detecting duplicates. A true match should always look at the EXIF - is the EXIF matches, then the image is duplicate. The algorithm is flawed in LR.


PS: Refer to this for more details:
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Kingshuk Chatterjee

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Posted 6 years ago

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Rob Cole

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There are some complexities you've overlooked, or in any case not mentioned, for example, if there is no exif metadata, then duplicate detection must rely on file-attributes instead (or just not supported..).

Also matching info in exif does not necessarily mean duplicate (again, it depends on complement of exif metadata that is present). For example, if serial number and subseconds field included in date-time original, those two items alone are conclusive, if not then... (it's possible for two non-duplicates to have matching exif if definitive items are not present).

That said, I agree with you that the current import duplicate algorithm is weak.