One of the more exciting announcements from the otherwise slightly drab keynote at Macworld Expo in January was that iPhoto '09 would support geotagging. This is the practice of embedding the coordinates of where a photo was taken, invisibly in its metadata.
The problem is that few cameras record this information automatically, and adding it by hand is laborious. This little add-on, however, adds GPS to any camera with a hot shoe (realistically, this means very high-end compact cameras and essentially all DSLRs) and will add location information to all your photos automatically. Well, semi-automatically; read on.
The photoGPS itself needs to be charged, though it never ran out of juice in our days of testing. Location information isn't embedded directly into your files as you shoot. Instead, triggering the shutter sends a pulse to the photoGPS telling it that you've taken a photo, and it then notes where you were when that happened. (It was good at getting a pretty instant satellite lock – impressive given the shocking GPS-locking performance of the Nikon Coolpix P6000) It claims 10m accuracy, though in our tests it was at least twice as good as this outside.
When you then hook up your memory card and photoGPS to your Mac, the software looks at the date stamps in the photos, and matches these with the data for the GPS locations. We love that it doesn't just embed the coordinates in the files, but looks them up online and writes the proper longhand location – down to the street – into the relevant IPTC fields.
It also matches points of interest, something iPhoto can do itself. But, much of this information is also added as keywords, which can't be switched off. It's embedded into JPEGs, or added as an XMP sidecar for raw files; it worked a treat with our Canon EOS 400D.
The Mac software is sluggish, however, and not that friendly, and the unit itself falls out of the hot shoe too easily; a tightening screw would be welcome.