Geomet'r GNC-35 - Easy geotagging for the Nikon D300

Geomet'r GNC-35 GPS GeotaggingEver taken a picture and then a few months later wondered where it was taken?  Geotagging -- inclusion of GPS positioning data in an image file's Exif header -- is a useful feature that is available in some modern cameras that helps solve this problem.  Once you've got GPS data in your images, you use an application or a service to map the location of your images.  Their are an increasing number of devices that let you easily add the GPS data to your photo files. 

The Geomet'r GNC-35 is a $145 GPS receiver is one such device, a GPS reciever designed to tap into the built-in GPS support of the Nikon D200, D300, D2Hs, D3xs, D3 and the Fujifilm S5 Pro.  The Geomet'r GPS receiver is a 1 1/2" square device that is approximately 3/4" thick which mounts on the camera hotshoe.  It attaches, and draws power, through the remote 10-pin terminal connectors.  The low-power receiver (with a built-in rechargeable battery for memory and Real Time Clock backup) uses a very small SiRF Star III GPS chipset to capture GPS data from any of 20 parallel satellite tracking channels. 

To attach the receiver to the camera you attach the plastic hotshoe mount to the receiver using 3M Dual Lock patches.  Then slide the hotshoe onto your camera (it's a tight fit on the Nikon D300) and plug the data cable into the 10-pin connector.  The GPS receiver will tear away if necessary and protect the hotshoe mount (probably the reason for the two part mount).  Another minor issue is that the receiver large enough to block the full elevation of the flash unit. When you mount the receiver so its back end is flush to the back of the camera (so you can use the viewfinder without obstruction), it blocks the pop-up flash.  Luckily you don't have to mount it on the flash, you can mount it on the camera strap.   

To switch the GPS on press the power switch on the data cable and the receiver switches on--unfortunately the LED that shows you the receiver is on is on the underside of the receiver a bit hard to see.  About 3/4 of a minute later the GPS should have a lock on the satellite.  A satellite lock is indicated by a solid LED--again hard to see.  Luckily the LED is not the only indicator.  On the camera's top LCD display, a small GPS icon flashes to the left of the battery icon when the red LED is flashing. It stays on solid when the red LED is solid, so you can just read the LCD icon for your receiver status. Flashing means the device is trying to find a signal. Solid means it will record GPS data with your image.

After the Geomet'r is ready to use, simply take the picture as normal and your camera will write over 12 GPS parameters to the EXIF File--the most important being latitude, longitude and altitude.  Several photo applications including Lightroom 3 and Flickr can use this data to show you exactly where you took the picture on a map.   For example, check out the EXIF data of this picture I took in Maine http://www.flickr.com/photos/21327599@N00/2927886415/meta/  it shows the latitude and longitude.

The Geomet'r unit also comes with built in software that will let you view the specific location of your picture.  To be honest, since the data loaded so well in Adobe Lightroom, I didn't use the built in software very much.

The location data from the unit was flawless in my 10 day trip to Maine.  A couple of minor issues--I did forget to shut the unit off overnight and it did drain the battery.  Also, the unit's connector, connects to the camera at a sharp angle, making it harder to stow away.  If you go inside the unit will obviously stop tracking satellites--rather than imprint incorrect data it does not record any data.  To be honest, I wish this was a setting that could be changed at my discretion.  Overall an awesome unit and one that'll stay on my camera.