Newbie Qs about Geotagging with Canon dSLR

[Roger Spencelayh]

- my iPhone 3GS drains in maybe 2 hours (or less?), if I recall correctly, when using the GPS this way.

Just in case anyone is looking at using GPS on a Smartphone (and not trying to get into an anti-Apple war here  ) using an HTC Desire a couple of weeks ago I got about 7 hours life from the battery with GSM, 3G and GPS on (and with it automatically checking for mail every hour). Full track log written for the whole 7 hours. And then the battery died 

Roger

[jonb]

One other reason for using tracklogs is that if you use multiple cameras it's easier than having a separate dedicated GPS device for each camera. I've been using Breeze Systems' Downloader Pro to download and IPTC tag/caption my files from up to 4 cameras and it reads my Garmin's .GPX files to tag the photos. The GPS supports displaying time to the nearest second, so a photo of the system's display with each camera at the start of the day (or syncing the cameras with the GPS) is a relatively painless method of ensuring there isn't a problem with clock drift.

There's an interesting article here on the process and pitfalls of working with a light camera-based geotagging system at the current time.