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Fool On The Hill » Blog Archive » Geotagging Digital Photographs

Geotagging is a logical mash-up of GPS technology, digital photography, and digital mapping. In its most basic form you manually associate a map location with a digital photo. Photo storage sites like Flickr make this fairly easy. On Flickr, you can browse a map and see photos that were taken by other people at any location you might be interested in. Microsoft has a project called PhotoSynth that gives this process an injection of steroids.

Here is a typical Track Log on Google Maps with photo locations –

There are currently a few digital cameras that can automatically geotag your photos as you take them. These cameras have a built-in GPS device that adds position information to the Exif data that is stored in the photo. I fully expect this become a standard feature in the next few years. Cameras without built-in GPS devices can still get in this game by using an inexpensive external GPS Logger

External GPS Loggers are available in a variety of different types. Some are completely independent of your camera and record your current location on a timed interval, some are triggered to record the location by the camera when a shot is taken, and some can even communicate with the camera and record the location data in the photo as it is taken. As I started researching these different models, I was attracted by the Jobo Photo GPS (hotshot style $150), but many bad reviews dissuaded me (poor quality, falls out of hot shoe).

By far the largest class of loggers is the ‘large pack of gum’ style. You simply turn them on and attach them to something (camera strap) with a clip and off you go. These are getting smaller, but are still limited by the need to pack a fair amount of battery power for the GPS.

The basic parameters I used for deciding which model to purchase were:

  • No Additional parts (caps that can fall off and become lost)
  • Battery life
  • Track Log data format (standard or requires conversion or proprietary software)
  • Ability to tag Raw files (not just JPEGs)
  • Data transfer mechanism (Bluetooth, storage card, USB, proprietary, etc)

I read a lot of reviews and zeroed in on the AMOD AGL3080 ($65). The Amod’s major selling points are that it stores its track log data in the standard NMEA format and that it requires no additional drivers or software to transfer the logs to your PC (or Mac). You simply plug it in via mini-USB and it appears as a removable storage device (acts like a thumb drive). The unit has two buttons (on/off and mark) and three indicator lights (on/off, storage full, and GPS status). The Mark button allows you to manually create a data point say just before you enter a building where GPS coverage may be lost. By default the unit records a data point every second and although you can change this frequency, I saw no need to bother.

Once you have a log recorded in the Amod, you connect it to your PC and simply copy the log. Now comes the fun part where we combine this GPS data with our photographs. This is done with some special software that can match the time a photo was taken with the time provided by the GPS system for each data point we logged. This will generally work best if your camera’s clock is correct (synched to the actual time), but it’s not a necessity if your software has the ability to compensate for any differences (apply an offset). I shoot with a Canon camera and use the EOSUtility software to set the camera’s clock to synch up with my PC. Yes, I hear you saying, what about the PC? Most of the recent OSs have a built in option to keep the internal clock in synch with the Internet Time Servers, but it’s easy enough to perform this manually if yours does not. Of course the first time I used the Amod logger my camera was off by a bit over an hour (DST strikes again). The good side of this problem was that it forced me to figure out how to apply a clock offset to the data so the software could match them up correctly.

The last piece in this process is the geotagging software. The Amod comes with some software, but this was quickly rejected as it can not update images shot in the Raw format. The next two contenders were RoboGeo and GeoSetter. Both can update Raw images and both have very good reviews. GeoSetter is free, while RoboGeo costs $39. I am currently using GeoSetter and am satisfied enough that I haven’t even tried RoboGeo. Actually GeoSetter is VERY good and I couldn’t be happier with it. GeoSetter is feature rich and the developer is very responsive (he does accept donations).

The Geotagging workflow is quite simple:

  • Copy images to a folder
  • Copy GPS log(s) to the same folder
  • Run Geosetter
    • Apply any required clock offsets (software helps to figure out what the offset is)
    • Update the Exif data (XMP sidecar file for Raw images)
  • Geotagging Done! (continue with my normal Raw image workflow in Capture One)
  • When I’ve finished processing the images I upload the JPEGs to Flickr
  • I tell Flickr to add them to the map

I like this last step as I may not want to publish the exact location of some photos (like inside my home). I can see some occasions when I won’t bother with the Amod Geotagger, but it will become a part of my normal outdoor shooting procedure.

Here is where you tell Flickr to Add to Map –

You can browse the map to see what other have shot nearby –

I tried using the GPS in my smartphone to create a usable track log. This required some additional software to create the track logs (Efficasoft  GPS Utilities around $30) and the output format was non-standard. I had to convert it using GPSBabel (free). I soon tired of the extra steps and complications. The Amod in combination with GeoSetter is so quick and easy that for me to consider an alternative, it would have to have to be built into the camera.

Update –

Just a few thing to keep in minds as you Geotag your images:

  1. Always keep your camera’s internal clock set correctly. It’s so much easier to tag the images when the times match. The GeoSetter software does a great job. Even if you have it turned off for a few shots (or went indoors), it will interpolate along your track and add the “guessed” locations.
  2. Always do the Geotagging first when you are shooting in RAW. You want the location data in the Exif before you render your JPEGs.
  3. Flickr does not automatically add the location data to your images unless you give it permission here – http://www.flickr.com/account/geo/exif/?from=privacy
  4. When you Geotag inside of a home you may be creating privacy/security issues. I just manually locate these images (using GeoSetter) to the center of a nearby town. The logger doesn’t work well (if at all) indoors anyways.
  5. Print a cheat sheet with the basic GPS Logger instructions on it and keep this your camera bag. You will likely forget how to reset the unit (required when you move large distances) or what the various indicator lights are telling you (the dead battery indicator got me). The Amod unit is great, but the simplicity of the indicator lights and controls can cause confusion if you forget what they mean. Amod Examples –
    • Satellite indicator on solid means seeking satellite fix, Satellite indicator blinking means satellites are locked in (working)
    • Satellite indicator on solid for more that a minute or two – GPS reset may be needed (press and hold the mark button for 5 seconds)
    • Storage indicator on means full, Storage indicator off means storage space is OK
    • Battery indicator off means battery levels are good, Battery indicator on means the batteries are dead, and Battery indicator blinking means low battery level

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