Sony's GPS-CS3KA data logger replaces the CS1 unit and is offered as an accessory for the company's Cyber-shot cameras. However, it also works well with Alpha DSLRs and can be used with cameras from other manufacturers - as long as they record to SD, SDHC or Memory Stick Duo cards.
GPS receivers have been around for at least a decade, with ultra-compact units sporting mini-USB plugs available for the past couple of years. So far, all the models we've looked at have had too many limitations to be really useful to the types of photographer who might require them so we've held out on doing comprehensive reviews. With the GPS-CS3KA has a better product than previous units we've looked at and, although it's not perfect, it has enough to offer to make reviewing it worthwhile.
Essentially, GPS data loggers are designed to help you keep track of where you've been and provide a way to add location data to the EXIF metadata in digital image files. The value of this function is that you can use the information to find map references to places where you took each shot long after the picture was taken. You can also make use of facilities like Google Earth to map trips using this data or allow visitors to social websites to see exactly where you were when the shots you've posted were taken.
Build and Ergonomics
The GPS-CS3KA looks like a small, fat mobile phone. It has a white plastic case and a 26 x 16 mm monochrome LCD screen that displays both the menu for driving the device and the device's current status. The top panel slopes backwards and carries a large on/off button. On the right side (with the device facing you) are five buttons.
Angled front view of the GPS-CS3KA. (Source: Sony)
The top three are the navigation buttons and consist of up and down arrows plus an Enter button. Below this trio lies a Menu button that toggles between the Menu functions and the GPS receiver status screen (the default setting). The lowest button is a Hold slider that locks the unit into GPS triangulation mode.
Rear view of the GPS-CS3KA showing the memory card slot and battery. (Source: Sony)
The rear panel of the unit slides off to reveal a chamber for fitting one AA battery plus a memory card slot that accepts Memory Stick Duo and SD cards. Both alkaline and rechargeable Ni-MH batteries can be used, the latter providing slightly longer usage times. The Magic Gate technology offered with some Memory Stick Duo cards is not supported but the unit is compatible with SDHC cards.
The back cover is attached to the unit by a rather flimsy looking plastic strap. Fortunately, it fits snugly enough to prevent dust and moisture from entering under normal usage conditions (although the unit isn't waterproof). Just below the lower end of the rear panel is a mini-USB port, located beneath a lift-up plastic cover. It's used for connecting the GPS-CS3KA to a computer via a supplied USB cable.
The unit comes with a soft plastic carrying pouch that has a transparent front panel with a cover that clips over the top panel and is secured with a Velcro strip. A rigid plastic loop and Velcro belt tab allow the unit to be attached to belts, straps or clips.
In Use
Before using the device, you must check the location and time settings in the unit and enter your local time with respect to Greenwich Mean Time (GMT). This is necessary because all GPS tracking is based on the international time standard. If the time isn't set correctly, the correct location information will not be provided. Note: if you're travelling through different time zones you will need to update the time on both the device and your camera in order to keep in synch with the data from the satellites.
The next step is to check that the local time set in your camera(s) is correct with respect to GMT. Normally this only means fine-tuning minute and seconds settings because, if you've entered the time difference between local and world time the device will handle the rest.
Using the GPS-CS3KA is straightforward. Once the battery has been installed all you have to do is go outside, point the top panel at the sky and turn the device on. The GPS detector will search for positioning satellites automatically and, once it has found enough to provide an accurate position, it will display the triangulation coordinates for your location in degrees, minutes and seconds for both latitude and longitude. Pressing the Enter button when the GPS-CS3KA is active lets you toggle through three displays: the triangulation screen, current co-ordinates and current date and time.
Finding location information with the GPS-CS3KA. The left hand picture shows the LCD when the unit is searching for satellites. The right hand picture is the display shown when triangulation is achieved.
After the initial triangulation is achieved, the GPS-CS3KA will take a new reading every 25 seconds as long as it remains switched on and while sufficient power remains in the battery. A new log file is recorded each time the unit is switched on. The readings are stored as data logs in the on-board memory (approx. 128MB) even after the power is switched off. (To clear the data logs stored in the memory you must format the memory by selecting Memory Format in the Tools menu, which is accessed via the Enter button.)
For best results (quick triangulation and accurate tracking), the top panel of the GPS-CS3KA should point towards the sky. However, we found it would work quite well when carried in a shirt pocket and on a belt loop. It could also be attached to a camera backpack when you're bushwalking and it's light enough to clip onto a hat band.
Data cannot be collected when the unit can't communicate with the geostationary satellite network. Consequently, the unit won't work if you're indoors, in a tunnel or between tall buildings that obscure a large part of the sky. Communication will also be lost as you pass under bridges or dense vegetation; in fact anywhere the unit can't access more than about 30% of the sky. The satellite links may also be disrupted by strong electromagnetic fields (as you'd find near high voltage cables) or radio signals broadcast around the 1GHz band (e.g. from mobile phones).
To transfer the GPS data to the image files, you must insert the memory card from the camera into the card slot in the GPS-CS3KA. Close the back cover, turn the device on, press the Menu button then Enter and select Matching from the pop-up sub-menu. Then press Enter again.
Matching the GPS data log in the GPS-CS3KA to image files stored on a memory card.
The GPS-CS3KA will scan through the files on the memory card, looking for the time at which each shot was taken. It will then upload the corresponding location co-ordinates into the image metadata, one shot at a time. The device works in batches of 60 image files at a time. If the card contains more than 60 shots, you must press Start>Enter again to embark on the next batch of files. It took approximately two minutes to process each batch of 60 images.
Software
The software bundle supplied with the GPS-CS3KA consists of two applications: Picture Motion Browser V. 4.2.03 and GPS Image Tracker V. 2.1.00. Both are designed for the Windows operating system. (The device itself is also Mac-compatible, although no software is provided for Macintosh users.)
Picture Motion Browser (PMB) is the standard browser/file manager application that is supplied with all Sony digital cameras and camcorders. It takes over the uploading process and can be used to tag images and video clips with category labels and store them in folders for easy searching. Many different search options are supported, including a ‘Face Search' that can locate all files containing shots of a specified person.
GPS Image Tracker is a dedicated application that synchronizes the images on your digital camera with the latitude, longitude and time readings from the GPS- CS3KA device. Once this is done, it will display a Google Map showing where you took each shot.
You can match the GPS logs in the GPS-CS3KA to image files that have been uploaded to a computer by connecting the device to your computer with the supplied USB cable and using the bundled GPS Image Tracker software (see below). By circumventing the standard card-based system, this enables you to transfer log data to images that were recorded on other types of memory cards.
Transferring GPS data to stored images is easy. Simply select those images you want to apply positioning information to and drag-and-drop them onto the image file list in the right hand side of the main window in the software application.
The main window in GPS Image Tracker. The right hand column shows the files selected for data synchronisation. The map of the places in which these shots were taken is located in the top half of the main window, while the actual data for each shot can be seen below it.
Importing logs for shots already stored on a computer.
You can zoom in on a specific area where a number of shots were taken.
You can also select individual shots and view the GPS data they contain - or transfer GPS data one shot at a time.
The images are automatically matched with any GPS logs the software finds, as they are transferred. The system is compatible with all images that support Exif 2.1, provided they contain time stamp information. This includes images and video clips from other manufacturers' cameras. Once files have been tagged with location data, any application that can read EXIF data, such as Flickr, will be able to map the shot automatically.
When images tagged with GPS data are subsequently viewed in Picture Motion Browser, the locations where shots were taken will be identified by push-pins on the map. Clicking on a pin displays the image taken closest to the marked spot.
The Map View option in Picture motion Browser lets you see which shots were taken in selected locations.
Performance
Provided you have set up the time synchronisation correctly and remain within the capabilities of the device, Sony's GPS-CS3KA is an above-average performer and certainly the most capable unit we've used to date (although we've only tried a few). In our tests, it managed to get the location of shots correct to within 10-20 metres when the readings were taken while we were walking around. This should be adequate for most potential buyers.
Using the software was very straightforward and the device worked faultlessly when plugged into a USB port on our computer. Battery life was very close to specifications.
Buy this device if:
- You want a GPS data logger that is easy to use and works effectively in outdoor locations.
- You are prepared to keep updating the local time zones on both camera and GPS logger as you travel.
Don't buy this device if:
- You want to track journeys that will be made mostly in a plane, car or train - unless you have the opportunity to take periodic readings from satellites to obtain positional information.
- You require better than one-metre positional accuracy.
- You require a longer continuous battery life than approximately 15 hours.