Added 2008-7-13: See here for a complete geotagging workflow on the Mac!
Manual geotagging is a slow and boring process – provided you remember the locations the photos were taken at. I’m convinced that it won’t take long until almost every cheapo digital camera comes with its own GPS receiver that automatically stamps the coordinates into the EXIF header but unfortunately, we’re not quite there yet. So the main question is: how do I get the GPS readings into the EXIF header of the photos in my Nikon D80?
Unfortunately, the Nikon D80 doesn’t come with a data connector like the more expensive Nikon bodies. So there’s absolutely no way of directly stamping GPS information at photo-take-time. A less elegant approach works like this: A GPS logger device is permanently recording my current location and when I’m back at my notebook I download the GPS track log from the GPS logger and merge it with the photos I took on the same day. The EXIF information of all D80 photos contain the (camera-)time the photo was taken at so there’s going to be a close or even exact match of the photo time information and the recorded GPS logger coordinates and voilà: that’s the location the photo was taken at. I know this may not sound very sophisticated and involves some extra work but that’s as good as it gets with the Nikon D80.
Which GPS logger best suits my needs
My needs are:
- Quick and easy battery replacement using standard batteries. Some GPS loggers come with their own (proprietary) rechargeable battery and charger and there’s always a risk that the battery isn’t charged when you need the device. I’ve got already enough chargers, cables and stuff with me when I travel so I’m really looking for something simple and stupid. Another advantage is that you can buy standard batteries almost everywhere.
- The GPS clock and the camera clock need to be synchronized (the GPS clock being the master). I prefer to have a display on my GPS logger that shows the exact GPS time so I’m able to make sure both clocks are in sync.
- Continuous run time of at least 12 hours and enough location storage for the same time.
- Bluetooth support (my notebook has Bluetooth built in) so I don’t have to mess around with more cables.
- Needs to fit into the outer compartments of my LowePro camera backpack.
- Adjustable logging intervals.
- PC and Mac compatible. I don’t mind installing some additional software and drivers on the Mac.
- Low costs because there are going to be better loggers with better software support in the near future as geotaggig becomes more popular.
There aren’t too many GPS logger review sites but I do recommend Richard’s Tech Review blog for reviews on various GPS loggers. It seems that the only low-priced GPS logger with a LC display is the Holux M-241. The LCD even has a backlight which turns itself off after a few seconds after pressing a button. This is an advantage compared to the non-LCD GPS loggers which use bright blinking status LEDs which might accidentally interfere with your nightshots.
Richard’s review on the Holux M-241 wasn’t that positive but it’s the only device that suits my needs. Looking at the cons Richard lists for this device I can’t see a point that’s a show stopper for me. One nice thing about the Holux M-241 is that it’s fully functional when plugged into an USB port even without a battery (using the included USB/Mini-USB cable). This way you’re able to download the data even if the battery is empty.
As the Holux M-241 isn’t being sold in my country (Switzerland) I decided to buy one from eBay from a Taiwanese seller named “plum.bargains” for US$81 including shipping. I paid with Paypal and it arrived after one business week.
The Holux M-241 sports a dot-matrix LCD module. I was quite impressed by its resolution.
Pedestrian use and static navigation
The Holux M-241 uses the MTK GPS chipset. I gathered from a few GPS-geeks forums that the MTK chipset is more optimized for speeds above 5 km/h than for pedestrian use. The feature is called “static navigation” (SN) if you want to google more information about it. It’s being said that GPS loggers with the SiRFstarIII chipset provide more accurate readings at slow speeds because SN can be disabled on those chipsets. I can’t really validate this claim as I only have a MTK based device but I can tell you that the Holux-M241 is pretty accurate in every situation as long as you take care that the side marked “up” always faces the sky. It’s a non-issue for me personally.
Geotagging photos using the Holux M-241
The provided Windows utility from Holux has a few ugly bugs so I decided not to use it at all. It won’t run on a Mac anyway and I was looking for a solution that covers both operating systems. Thanks to a link on Richard’s blog I found the BT747 project. It’s a platform independent (using Java) datalogger control software. It may not look extremely fancy but hey, it gets the job done. My Kudos go out to Mario from the BT747 project for his awesome work!
The firmware in my Holux M-241 is labeled “B-core_1.1”.
In case you want to run BT747 on a Mac, Richard provides some instructions how that can be done.
Once the BT747 software is up and running you can download (using Bluetooth or USB) the track log from the Holux GPS Logger and decode that information to various formats (NMEA, GMAP, TRK, KML, CSV, PLT…). The format you choose will depend on what software you plan to use to geotag your photos with. I’m currently using GeoSetter for Windows which works nicely with my .DNG Adobe Lightroom photos (converted RAW .NEF files from my Nikon D80).
Awesome: GeoSetter fetches the precise altitude for a given location and textual location information online from the web and puts them into the EXIF header.
I’m still looking for a similar software for the Mac that processes .DNG or .NEF files. Please leave a comment if you have a suggestion.
It would be very clever if Lightroom itself would be capable of geotagging my photos using existing NMEA track log files when importing photos from the camera.
The Holux M-241 combined with the awesome BT747 and GeoSetter applications are an inexpensive and powerful combination for everyone who owns a Nikon D80 (or almost any other camera) and wants to start geotagging her/his photos. Please don’t forget to donate to those projects if you use them.