iPhone and Geolocation

Recently, I have become interested in Geotagging images for use in Lightroom. Lightroom supports images that have been Geotagged but not ‘official’ in app Geotagging (Note that there are Plug-ins to assist with this from Jeffrey Friedl and Jeff Barnes). Before spending money on a proper GPS device, I decided to investigate what could be done with the apps and devices I already owned.

HoudahGeo for Mac and RoboGeo for Windows are highly regarded GPS tagging software apps and these offer a connection to Google Earth, so you are able to locate where you were when you took the images to Geotag. Obviously, the main drawback with these apps is that a) you have to remember where you were when you took the images and b) it won’t be as accurate as a proper GPS device.

Both also accept files from GPS devices and after a bit of reading on the subject, I saw it was possible to use the iPhone as a proper GPS device. To facilitate this, I downloaded Trails which was recommended on the HoudahGeo website (apparently for a $1.99 app it is more accurate than a $200 Garmin device!). Once loaded, you set Trails to run while you are on a photoshoot.

It is worth mentioning that Trails needs to be running all the time, so you will want to ensure your battery is fully charged or even have a backup battery, and to turn off your Auto-Lock in settings. You will also save time if you can align your iPhone and Camera clocks, so there is no time offset to worry about.

In the Settings screen I set it for Hiking (which was the nearest I could think of to a photoshoot!) and entered my email address, which is needed to email the files Trails creates.

In the Main screen I setup a new ‘track’ called Forty Hall, and set it to Record. Then as with normal GPS devices, it locks onto a signal and starts logging GPS information.

Once you have finished, then you ‘slide to stop tracking’, this lets you view your journey, as a list, as a road map, as a satellite view or as a terrain view with or without the altitude.

To use the GPS location information you email the .gpx file to your email address and align this information with the images you took.

I use HoudahGeo on the Mac, so my workflow is to:
1) Save my current Metadata in Lightroom, this ensures I have all the other edits made (such as Keywords and Copyright info) in the file.

2)Drag the images to HoudahGeo and they appear in the main window.

3)import the GPX files. (using the Load GPS data from file button). Houdah Geo supports GPX, NMEA, CSV, and Sony LOG files. Tracks saves its data in the GPX format.

The images get the correct GPX data added – it works out when the photo was taken – the guesses it makes seem accurate but you may want to double check to make sure.

Once you have done this and saved the GPX data to the DNG files, return to Lightroom, select the images you have added the GPS information to, select Metadata > Read Metadata from File…

houdahgeoscreensnapz002

This will read the updated Geolocation metadata, and Lightroom will display the link to the Google Earth Map and the GPS information. If you Option/Alt click the link you get sent to Yahoo Maps.

Lightroom EXIF information

The Trails website also has an article on this subject.