| Joined: | Mon Apr 2nd, 2012 |
| Location: | South Lakeland, UK |
| Posts: | 4066 |
| Status: |
Offline
|
GPS units have obviously improved over time since their introduction. My first one worked with an early USB era Mac Laptop and is magnetic, clamping to the car roof like a little black limpet, worked with a USB Lead. I don't seem to be able to get software that's compatible with my current gear so it's hanging on a cabinet nearby, unused.
Have tried a variety of different units but the most accurate one I have is my Garmin 'GPSmap 60CSx' which I reckon is accurate to about half a Metre, but dependant on a clear sky.
GPS works by comparing the times received from multiple satellites around the world and computing the location based on the comparison between the tiny differences in the times received from each satellite and a lot of mathematics. To get great accuracy, top quality components in the receiver and the calculator are a essential and expensive. Cloud cover and trees/buildings do affect the accuracy. Some now also tap into the cellular phone mast network to improve accuracy I believe.
I know JK has tested a variety of 'on camera' units but I think for most purposes a cheap tracker GPS creating a time log combined with the images is a pretty good method to set the GPS. I think Lightroom can ingest the tracker log to combine with the images to generate the locations. In my experience toe EXACT location of each image isn't needed because a glance at the image should give that... What's needed in practice is a grouping of all images at a given general location, in my opinion having a lot of images each with a slightly different (and possibly slightly inaccurate) location isn't helpful. You will get a snail-trail effect around a site when all you really need is a central locator on the site.
____________________
Robert.