Image capture, Google Earth, by Evan Robinson
Because I use a Canon, I don't have an easy option for GPS equipping my SLR. So if I want to geotag photos, I have to find a less integrated solution.
The cheapest solution is to manually tag photos using some kind of map software. Aperture provides the Places feature to do this. There are plug-ins (I downloaded and tested Maperture, which worked fine). Flickr lets you put photos on a map, and I imagine that other photo hosting services provide similar services.
But geotagging thousands of images manually is a pain, and it will continue to be a pain. In vernacular of my day job, it does not scale. I have thousands (maybe tens of thousands) of untagged photos, and I will be generating many more. On an ongoing basis, manual geotagging is right out.
That leaves some sort of GPS logging. There are many devices, including many if not all smartphones and standalone GPS units, which will periodically record your GPS position for later use. These log files can be imported and converted for use with Google Earth and other software to track your position over time.
I have an iPhone, and could well have found logging software for it. But I have several use cases counter to that solution, especially long periods out of phone service (camping, hiking, the Big Island, etc.). I suspect that running logging software on the iPhone would reduce battery life below my minimum needs.
So I went looking for a standalone GPS logger. My search was complicated by the fact that I'm a Mac user, of course. Google and Amazon led me to a set of five possibles (prices at Amazon):
- Amod AGL3080 ($65)
- Qstarz BT-Q1300S ($100)
- Holux M-241 ($66)
- Columbus V-900 ($102)
- Sony GPS-CS3KA ($94)
My first test was basic functionality: I turned each device on and carried it for a day or two. The QStarz and Columbus units had a really hard time getting GPS lock in downtown Seattle, so they were out. Next was communication with my Mac. I got the other units (Amod, Holux, and Sony) to talk to my Mac. Next I compared the tracks with my actual paths. That eliminated the Amod, which apparently had trouble getting a good position even when it said it was locked on.
The Holux and the Sony passed all the basic tests. Both these units use single AA batteries (I use Eneloop rechargeables), which is a plus because they don't require special chargers or cables. Both connect using standard small USB connectors, which is a plus because that's the same cable I use to talk to my external USB drives. Both have screens, which means they don't require specialized (usually Windows-only) software to configure them. The Sony has a nicer form factor and carrying pouch and supports on-card geotagging of photos. It also connects to the computer as an external drive, which makes acquiring log files very easy (the Holux requires a special USB driver be installed and software to pull log files off the device). The Holux can be configured for more different logging options (log every 1, 5, 10, 15, 30 seconds; log in metric/english measurements; log based on distance moved; etc.) and seems to use less power. It also appears, in my basic testing, to lock on faster and more reliably. It's also about $30 cheaper. And it has the only toggle power switch in the bunch (every other device uses a push button of some kind to turn the device off and on, sometimes holding it down for X seconds to turn on and Y seconds to turn off -- a toggle switch shows you instantly whether the device is supposed to be on or off, which helps diagnose dead batteries, among other things).
Geotagging workflow on the Mac with the Holux M-241
The first necessary activity with the Holux is to get it to talk to the Mac. I had to install a special USB driver, the SP210x USB to UART Bridge VCP Driver. Once that was done, the Holux talks to the Mac through a standard USB cable, and logs can be acquired using free software called HoudahGPS, which is a graphical front end to gpsbabel.
If you are only going to acquire log files, HoudahGPS will do you. It reads data off the Holux and converts it to several standard formats. If you want to view your track in Google Earth, for instance, this is how you do it.
If you want a standalone geotagging app, HoudahGeo ($30) is what you need. I had a license lying around from some Mac Bundle or another I'd acquired, so I didn't actually even need to buy the software. HoudahGeo includes HoudahGPS' functionality and can extract GPS information from the Holux directly, without using HoudahGPS as an intermediate.
How you use HoudahGeo will depend upon your existing workflow. I use it as part of pulling photos off my cards. I copy the files off my card to a standard location, run a couple of droplets on them to separate the images by day shot and rename them to my standard (YYYYMMDD-###, which will have to change to -#### or even -##### because of the speed of the 60D). Then I drop the resulting folders on HoudahGeo, which imports the Canon Raw (CR2) files and associates them (by timestamp) with the positions logged on the Holux. Getting the log into HoudahGeo can happen two ways: direct import from the device, or by using HoudahGPS to extract the log file from the device and then using HoudahGeo to import the log file (which is obviously more work, but it's the way I did it first, so I know that it works as well as direct import). HoudahGeo can be instructed to wipe the log file from the device after import.
There is one thing which you must verify in order for all this to work properly and relatively automatically: Your camera's clock must be closely in sync with GPS time. This is one reason why the screen on the M-241 (and the Sony) is so important: it allows you to see GPS time and set your camera time to a close match (I find that within a second or so is adequate).
HoudahGeo will automatically associate GPS position data with photos according to timestamp. Since I've set my camera time to closely match GPS time, it's been seamless. Without that match, it's a #@&%^@(# pain in the butt.
HoudahGeo is then happy to export the CR2 files with GPS information embedded in metadata (it's entirely possible that sidecar files are in use here, but I don't know and for now I don't need to know -- it just works). Once the files have been tagged with the GPS information, I import them into Aperture as a Project.
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