The LCD display is also useful, since it can display the time and location data acquired from the satellite signal. The time display is used to synchronise your camera's internal clock with that of the satellite, essential for accurate positioning, while the location data, displayed as latitude and longitude in degrees, minutes and seconds, can be used for navigation purposes if you know how to read a map. This data is not directly available from the Sony device. The ATP's display is a bit annoying though; it is of the type that is black with lighter lettering, making it difficult to read in bright light, and it has a stupidly quick sleep function which shuts the display off after just five seconds, presumably to save on battery power.
In actual use the ATP Photofinder is very simple to operate. It is activated by pressing and holding the power button for a few seconds, whereupon it attempts to acquire a signal from the GPS satellite system. I found that when first activated, it took around ten minutes to acquire its signal, but was much quicker on subsequent uses, connecting in a couple of minutes. Like most GPS devices it is not capable of picking up a signal inside a building or in a car, but outdoors it worked very well most of the time, although I did notice that it lost its signal when standing on the north side of some tall buildings. I took it out for a walk around my home town, taking a series of photos at local landmarks along my way. When I got home I inserted the camera's memory card into the unit, and it took about a minute to add the GPS location data to the files. It's worth noting at this point that the Photofinder only supports JPEG files.
The manufacturer recommends the use of Google's free photo management program Picasa, which includes an option to display "geotagged" pictures on Google Earth, the global mapping program also available for free download. Like most civilian GPS systems the claimed accuracy is in about ten metres, but I found that while some photos were positioned with pin-point accuracy, many were positioned as much as 100 metres from their actual location. It is possible that some of this inaccuracy can be attributed to errors in the position of satellite imagery in Google Earth, but in some cases the Phototracker was clearly at fault, for example flagging two picture at the same location even though they were taken several hundred metres apart. The reason for this is that if the unit cannot get a signal for part of the time, it attempts to estimate the location based on the time it was taken and the last known position. This is fine if you're travelling in a straight line, but if you move around a lot it can get confused.