Holux M-241 GPS Logger field test

We just returned from a two week holiday in Scotland. I hauled my complete photo gear (which added almost 10kg to my backpack…aww) with me because I planned to spend quite some time photographing. It turned out that the scottish weather can be rather challenging to the passionate photographer but that’s another story. Of course I took my Holux M-241 GPS logger with me because I wanted to geotag all our photos. I also decided to take my small 13″ notebook with me, just in case the GPS logging device runs out of storage. As it turned out at the end this wouldn’t have been necessary. More on that later on.

I just took a few AA-batteries with me so we went to a Tesco supermarket and for some reason I bought a 12-pack Tesco-branded cheapo batteries. Soon it turned out to be a bad decision because the M-241 ran out of battery after about 3 hours of logging. After that I bought some decent Duracell Plus batteries and got about 10-11 hours of logging with them. I could leave the logger turned on the whole day without worrying about it. My advice: don’t save on batteries. Buy some high quality batteries to make sure you get a decent run time without having to check the battery indicator every now and then during the day.

I’m always using a 5 second logging interval on the M-241 and using this setting the M-241 was able to cover the entire journey without running out of space. The M-241 can save up to 131037 GPS records. This results in 15 twelve-hour periods with a 5 second interval. That easily covers a two week holiday and in most cases even a 3 week holiday. If you want to have daily backups of the log records you may want to take a notebook with you or consider buying one of these small netbooks which are ideal for traveling.

When I got back I downloaded the log records using BT747 to my Mac and converted them to a Google Earth .kml file. Of the 1500+ photos we took only a third survived the selection process and so I ended up with 493 nice photos in Aperture 2. I imported them into a new Ovolab GeoPhoto project and selected the rather large (21 MB) .kml file as track point source. It took GeoPhoto a long time to match the 53000 or so track points to my photos. It even looked as it had crashed (spinning beachball). But after about 5 minutes all photos showed up as geotagged. See my post about geotagging on the Mac for more information about the geotagging workflow I use.

This screenshot shows the geotagged photos with GeoPhoto’s Google Earth integration.

Someone reported a problem with corrupted data when his M-241 ran out of battery. I ran out of battery about 20 times in the last two weeks but this problem never showed up.  When trying to open the .kml file with all the 53000 track points Google Earth finds some weird dates in the file which date back to 1935. At this point it’s under investigation whether this is just a conversion issue or if the Holux indeed reported wrong log records. This may have been occurred when the battery ran out of power while writing a log record. Whatsoever, it would only have an impact if you want to have a look at your route in Google Earth or Google Maps. It will most likely have no impact on the photo geotagging process itself.

Make sure you always use the latest firmware version though.

I’d like to conclude this post with some impressions from Scotland.

8 replies on “Holux M-241 GPS Logger field test”

  1. Wow lovely pictures of Scotland – looks like you had a great holiday :)

  2. Last week I bought a Holux M-241 and a little confuse to operate it, especially how to tagging GPS Log to the pictures.
    Lucky me…to find your blog… now I can operate my Holux M-241 well… Thank you

  3. “my small 13″ notebook with me, just in case the GPS logging device runs out of storage”
    -> Now your Java Phone will do ! (BETA J2ME Version of BT747 is now available).

  4. That’s true Jan, I don’t see the need for using waypoints in geotagging photos either when it works so well automatically. However, if you want to geotag and record track logs with points-of-interest simultaneously it makes the world of difference. For example, I will use the same logs to show our itinerary with precisely-located POIs that can be downloaded and exported for use with a TomTom/ Garmin PND.

    The deer was near Bridge of Orchy, semi-tame I think because of its proximity to the rest area, but not tied up nor fenced in so not entirely safe ;-)

    Do you really think going from a 5 to 10sec interval would have a significant impact on battery life Jan? I’d assumed, perhaps incorrectly, that signal reception was a passive affair. It would be an interesting test to carry out if we could somehow account for variation between batteries…

  5. Bruce, you really got some awesome photos in your gallery. I’m amazed how close you got to that deer AND managed to get a good shot at it. By the time I fumbled my heavy tele lens and converter out of my backpack they were always at least a mile away. You also managed to find a perfect “phone booth in the wilderness” motive :-)

    I didn’t use the M-241 to mark waypoints. I just left it running the whole day. Chances for an exact match between a log record and a photo are very high so I didn’t even think about pressing buttons on the logger.

    I’m thinking about going to a 10 second interval instead of 5 too if this further extends battery life on the M-241 but I guess it will be about the same because writing to memory doesn’t use a lot of power. But tracking the GPS signal does.

  6. LOL; we just returned from a two week holiday geotagging in the Highlands too :-)

    I was planning to take the M-241 but was concerned about battery life, since I wanted it to log from the time we went out the door until we got in for the evening i.e. from breakfast until after dinner, covering some 1768 miles. So I took the Mac-friendly BT-335 which logged at 10 sec intervals for two such days, before I recharged it “just in case”. We did have a laptop, so I did do daily log downloads. Amazed at how many places (all but one) we stayed in offered WiFi, so GPSPhotoLinker could perform reverse geocoding via a server (Geophoto can do that offline, to its credit).

    Did you use the M-241 to mark waypoints? Until I read your update and checked out the new version of BT747 I didn’t realize it could now distinguish waypoints from track points (see here), a feature sadly lacking with the BT-335/ DG-100 units I’ve tested.

    You got some really super photos there; I use Gallery 2 with the Google Maps module to display geodata (see here for my Scotland pics).

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