Last week on Mac Power Users we discussed iOS photography workflows with Jeff Carlson. I shared how I used a Kingston MobileLite Wireless to backup photos taken on vacation, as well as import those photos to my iPhone's camera roll for sharing.
Unfortunately, whenI returned to my home Wi-Fi ended up with two and sometimes three copies of the same photo uploading to my iPhoto library thanks to my overly-paranoid photo backup and automation routine. I had enabled PhotoStream and my Dropbox and Eye-Fi photo downloads were auto-imported into my photo library via Hazel rules I configured before I left. Before I realized, I had imported over, 3500 photos into my iPhoto library and had many duplicates.
I inquired on the podcast about an App that would remove duplicates from an iPhoto library. As always, our listeners responded. Magnus pointed me in the direction of PhotoSweeper, available on the Mac App Store for $9.99. PhotoSweeper works with iPhoto, Aperture and Adobe Lightroom libraries or will also work with a folder of photos in all the standard file formats.
PhotoSweeper was able to analyze and identify duplicates and automatically choose the best photo to eliminate based on configurable criteria. You can choose to only identify exact duplicates (which is what I did to start) or you can choose photos that are similar which is helpful if you're trying to weed through a slew of photos to find the best shot and eliminate the rest.
The application was fast and surprisingly accurate. I could not identify a single error when asking it to remove only exact duplicates. It analyzed over 3,500 photos on my MacBook Air (2 GHz Core i7, 8GB RAM) in less than two minutes and saved me over 3GB of hard disk space.
There's a Lite version available for $4.99 which will find duplicates and similar photos, but doesn't provide comparison options or advanced features. For the extra $5 I'd recommend going with the full version as this is a tool I could see myself using again. You can also download a demo on the developer's site.
As a side note, I had a few people write in and recommend Gemini which is a good duplicate file finder that claims support for iPhoto libraries. I already purchased Gemini and ran it on my iPhoto library, and it found a few dozen duplicate photos, but PhotoSweeper found over a thousand. If you suspect you have duplicate photos in your library you want an App designed for photos.