How to find duplicate images on a external hard drive?

[perryj]

I have two external HDD that I back up iphoto and aperture too. I have been using one of them for 3 years now and I am sure there are many duplicate imagines on them, is there a fast way to find and delete duplicates ?
Thanks !

 

[SilentPanda]

I've had pretty good luck with Duplicate Image Detector.

 

[davegregory]

I've used TidyUp! and it works really well. You can find it here

 

[Lola M]

Tidy Up! v2. It has Aperture and iPhoto plugin. Very simple and easy to use.