i am infamous for duplicating images and stickingt them in different places on my computer. macbook pro mid 2009. I also have several photo editing apps (standard apple, plus lightroom, pixelator, acorn, intensifiy and more — and I think/worry that many of them independently download the pictures from my camera creating even more duplicates. Regardless, I had 15,000 pictures from tiff images that I created with the grab app to pics from my jpeg, etc. from cameras.
Although PhotoSweeper allows you to easily download pictures from multiple folders and libraries, I used Apple’s Find app to search for all images on my computer and then move them to all to a single folder on an external drive. I also emptied all the iPhoto and new Photos libraries, as well as lightroom cataloges, etc. (I figure I can put back whatever pics I want in each, when I want to) into that single folder. Then I selected that file through PhotoSweeper’s tool (again very easy). The program gathered all the pictures, fairly quickly considering how many I had. I pressed the combined button, and sorted the photos into groups of duplicate photos (side by side was my choice to display them). Again very quick considering.
I had the program auto-mark the ones to delete. I could have just delted the duplicates, but I want to check each one. I almost always chose to delete the pics that the program chose, but not always, and a few times I kept some duplicates for various reasons. Being anal about checking each grouping mean it took several hours, but if you are more fleixlbe and more organized, it could be done much faster. Once I was done reviewing each group, the program quickly got rid of the duplicates. I strongly recommned it, and I am not easily impressed by photo apps — which is why I have so many editing apps.