GPS tells iPhone and iPhoto roughly where they are
Mac Tip #379, 08 April 2009
The iPhone and iPhoto both work with GPS co-ordinates. Here’s how to see the co-ordinates, and manually check them on a map.
The iPhone and some cameras record GPS co-ordinates when you take a photo. For example, last year Dr Jane Goodall gave a talk at Wellington Zoo. I snapped a few photos with my iPhone. One of those photos, displayed in iPhoto, is attached to this Tip as a screenshot.
I don’t yet have iPhoto 09, which integrates mapping features with the GPS information iPhoto may hold for a photo:
iPhoto  helps you explore your travel photos with a new feature called Places. This feature uses data from GPS-enabled cameras or the camera on iPhone to categorize photos by location and convert GPS location tags to common, user-friendly names. So without any effort, pictures you took of the Eiffel Tower are labeled with easily searchable names like “France,” “Paris,” and “Eiffel Tower.”
Because I have iPhoto 08 I have to do the mapping work myself. Here’s how.
- In iPhoto select a photo that has embedded GPS information, such as a photo taken with an iPhone.
- From the Photos menu choose Show Photo Info. An information window appears that displays what iPhoto knows about this photo.
- If necessary, click the disclosure triangle beside Exposure to reveal Shutter, Aperture and other information.
- At the bottom of the Exposure section GPS data is listed. Unfortunately there is no way to copy and paste that data. On my photo the co-ordinates were given as:
- Latitude: -41° 19′ 24.00″
- Longitude: 174° 46′ 35.40″
- Go to Google Maps in a web browser.
- In the Search Maps text area enter the GPS co-ordinates, like this:
-41 19 24.00,174 46 35.40. You don’t need to worry about trying to enter the degrees symbol, or the minutes or seconds symbols, but do leave spaces where those symbols would be.
- Click the Search button. Google Maps will display a map with a red marker at the location where the photo was taken. With any luck it will be the correct location. If you look at my second screenshot though, you’ll see I’ve drawn a couple of red boxes. One contains the Google Maps marker, the other shows roughly where the photo was actually taken. That means it’s off by around half a kilometre (around a third of a mile).
The good news is that the co-ordinates have shown me very approximately where I took the photo — handy for reviewing travel photos once you’re back home. The bad news is that this data can’t be relied on to pinpoint where a photo was taken, so don’t take anyone to court based on this information.
I’ve found my iPhone’s GPS co-ordinates to be quite often misleading, so I went in search of ways to correct it. More on that in a future Tip (once I’ve had a chance to see if the fixes I found actually make a difference.)