How to eliminate duplicate copies after doing a sort

Question

I did a filter/sort across 100's of folders then exported the results to a separate folder.
I later noticed way too many duplicates in the new folder.
Does Lightroom have a feature to automatically remove or eliminate duplicates when doing such a process??
If not, any other ideas??

Answer 1

Spaceman, you're basically correct that LR doesn't write your changes to the original file itself.  LR is a non-destructive editor, which is really a good thing. It means that if you screw up an edit, you can always go back and start over. Or if you decided to convert the image to B&W, and now want to go back and re-edit it in color, you can do that. There are, however, a couple of ways to do what you want.
The easiest way is to use the Export dialog. This will create a copy of your image(s) with all the edits applied. Those copies can then be viewed in any image viewer program. You can export as jpeg or tiff files. Based on your question, I'm guessing you typically shoot and process jpeg files (since most image viewers won't display raw files), so LR will create new jpegs, with all your edits. You can give these files new names on export, or write them to a different folder. You can even automatically import the images into the LR catalog if you want. (I don't, as if I ever want to re-edit the images I'll start with the original file.)
LR can also write the changes to what's called a "sidecar" file, that you can copy along with the original image file.  But I don't think very many apps know what to do with that file, either.