GPS for 5D3

AndrewG wrote:

The iPhone unquestionably has real GPS (since the iPhone 3G four years ago) — in fact, in certain ways its GPS is quite a bit better than “normal” GPS, because it can use Wi-Fi signals to achieve position lock much faster than with GPS alone. However, like almost all non-dedicated GPS units, its antenna is very small, and so it won’t get lock in many cases where a dedicated, standalone GPS unit would.

I’ve been using a Garmin eTrex HCx (and now about to upgrade to a Garmin eTrex 30) for years with my EOS cameras (first the original Digital Rebel, then 5D, soon 5D3). You sync the camera’s time with the GPS unit, leave the unit on, then use a program (I’ve been using HoudahGeo) to stamp the location data into the EXIF data in your images.

Advantages: the GPS unit will go 40+ hours on one set of lithium AAs; it picks up signal many places a non-dedicated GPS won’t; much more flexibility (e.g., if you go inside, your Canon GPS will lose signal and just not timestamp a photo, but you can tell HoudahGeo “interpolate between the nearest timestamped GPS locations as long as they’re not more than 30 minutes nor 500 meters apart”, which is awesome); and you, well, have a standalone GPS unit, which I love for hiking.