So, where was this taken?

If, like me, you take lots of photos on long days out, you may sometimes find yourself in the frustrating situation of not being able to recall where a particular photo was taken. Even though I write down all my movements for my blog, I still get caught occasionally and have to spend time and energy trying to locate a particular scene.

Wouldn’t it be good if, along with the other data on exposure, date and time, the camera also recorded the location of the photo? Well, this may no longer be the extravagant dream it might once have seemed. Up there in the sky we have those expensive navigation satellites beaming back data that is free for all to use and the market is already cracking at the seams with “satnavs”, electronic devices that can tell us where we are, even in the middle of nowhere, and show us our route from A to B on a map. Can’t this technology help us?

Yes, it can, and the keyword here is geotagging. This means attaching to a photograph (or, I suppose, any other artifact) the precise co-ordinates (usually latitude and longitude) of the place where it was taken. The question is how, exactly, this wonder is performed.

To start with, there are already some cameras on the market with geotagging built in: click the shutter and you get a photo and also the coordinates of the spot on the face of the earth where it was taken. If your camera has this, you are probably home and dry and need read no further. However, the rest of us are not so lucky and need to look for alternative approaches. I have been doing this and am passing on what I have learned.

In this post I will describe the sorts of generic devices available but not review specific models.

Devices of interest to photographers can be roughly divided into two classes, geotaggers and travel recorders. Needless to say, travel recorders often come with software to carry out the geotagging process. Both sorts record way points (the coordinates of the place where you are at that instant) and enter them in a log file for scrutiny later on. This information is usually formatted according to a protocol called NMEA, and although this is hard for humans to read, there is plenty of software available to turn it into intelligible output.

Among the geotaggers, we can distinguish 3 different types that I will call the Press-Button (PB), the Stand-Alone (SA) and the Camera-Shoe accessory (CS), respectively.

The PB takes a satellite reading and enters a way point in the log whenever you press the button. In between, it does nothing. To use it to locate your photos, you have to remember to press the button every time you take a photo or a closely grouped set of photos. Afterwards, by comparing the times of your photos with the times of these way points, you know where the photos were taken.

This system has the merit of simplicity but it does depend rather critically on you remembering to press the button. If you forget, then there is no way of locating your photos except by use of good old fashioned memory.

The SA, in contrast, continually records your position every few seconds. At the end of the trip, you insert the device into its base unit, along with the memory card from your camera, and it geotags your photos, adding geographical coordinates to the EXIF data of each photo.

Unlike the PB, this device allows you to switch it on and forget it until you are ready to geotag your photos. Another advantage, and a major one for some people, is that you do not need a computer. The device and its base unit do everything.

The CS is similar in conception to the PB, except that it is automated. You slot it into the accessory shoe of your camera and every time you press the shutter, the camera sends a signal to the device, causing it to record a way point. These way points are later matched up with their corresponding photos. Note that although it sits in the camera’s shoe, the device does not communicate with the camera. The geotagging is done later by software.

The advantage of the CS approach is simplicity. A disadvantage is that you may find it inconvenient to have the device permanently on your camera while in use, especially if, like me, you tend to put the camera back in the pouch between shots.

If all you want is to geotag your photos, the above devices will be perfectly adequate. For much the same money, however, you can have more. For example, how about producing a map showing the location of your photos or even a trace of your entire journey? In my view, if you are going to spend the money, you might as well have the full works.

If you agree with me, then what you need is a Travel Recorder (TR). There are several models on the market and they all do much the same things, though some do them better than others.

How the TR works is thus: you switch it on and it continually records way points every second or so (in some models the interval can be chosen by the user), giving you a complete log of your journey until you switch it off. The data recorded typically include date, time, latitude, longitude, altitude and speed and probably a few more things.

The software (supplied or bought separately) will reproduce the NMEA logs in readable or graphic form, e.g. as a readable text file or a plot on Google maps. It will also geotag your photos, so that the location of each photo is permanently available in its EXIF data. To check where the photo was taken, you can type the coordinates into Google maps.

Needless to say, there is more to the subject than that. There are some issues you have to consider. One of these is battery type and duration. Some devices have built-in rechargeable batteries while others use disposable batteries. Each has advantages and disadvantages. If the battery dies on you in the field, then if it’s a rechargeable, you are stuck with a useless device until you can get back to base and recharge it whereas if it takes disposable batteries, you just whack in a new set. On the other hand, disposable batteries can work out expensive in the long run, though I suppose you could buy the rechargeable variants and a charger.

Whichever sort of battery you use, how long it lasts is important, more so in the case of a rechargeable. Depending on model, battery life times can be as short as 8 hours and as long as 48 hours, according to what I have read. If you are using a rechargeable device, then you obviously need the battery to last longer than your longest photo shoot, so you probably need to look for a duration of 24 hours or more, to be on the safe side.

With disposable batteries, it isn’t quite so critical because you can put in a fresh set. The danger there is that you might not notice the batteries have run down and that you are no longer collecting data…

Another important issue is simply “How well do they work?” That’s a difficult one because while manufacturers and retailers list all the positive features of these devices they don’t tell you that, for example, “It doesn’t work very well in town especially among tall buildings”, yet this is the case for some models. All of them work fine in the open with unobstructed views of the sky but as you enter the town and then go into buildings, accuracy falls off and some stop working altogether.

This is where you need to read reviews, as many as you can get hold of. And read them with your faculty of discrimination turned to the highest level. Not all reviewers are as impartial as they pretend…

I have made a preliminary choice of travel recorder but—wouldn’t you know it?—all retailers seem to be out of stock currently. I emailed the manufacturer to no avail as they simply gave me the Web page of their “UK agent” who is out of stock like everyone else…

If and when I acquire my new toy, either the chosen one or another brand, I will report on it. I am quite looking forward to it.


About SilverTiger

I live in Islington with my partner, "Tigger". I blog about our life and our travels, using my own photos for illustration.
This entry was posted in Thoughts and Ideas and tagged , , . Bookmark the permalink.

2 Responses to So, where was this taken?

  1. cbramhall says:

    I’ve not tried it myself, but the latest version of iPhoto (part of Apple’s iLife suite) is able to use this information to display a map of where the picture was taken. (Even more impressively, since it doesn’t rely on satellite data, it can also learn recurring faces in order to automatically identify the people in your pictures).

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