A new GPS module designed for use with the latest digital SLR cameras from Pentax could help photographers who like to capture shots of the heavens avoid annoying star trails on long exposure shots. As well as adding earth-bound location information to images, the weather-resistant O-GPS1 unit also tracks the location and movement of celestial bodies and, with the help of the shake reduction system within the camera, shifts the image sensor in sync with the movement of the stars and planets.

The new Pentax O-GPS1 has been developed for K-5 and K-r cameras running the latest firmware, but will also work with the company's 645D model (although at the expense of some functionality). The unit attaches to the camera via the hot-shoe mount and adds geotagging information such as latitude, longitude, altitude, and capture time (universal time coordinated) of shooting locations to the image metadata.

This information can then be used to create personal travel journals or custom travel maps in applications like Google Earth, with images acting as pin points along the route and bringing the location to life when clicked.

Pentax says that the new module should acquire a signal from cold in about 40 seconds or around 5 seconds when hot, benefits from 50 channel tracking and is accurate to within about 32 feet (10 meters). There's support for terrestrial-based Wide Area Augmentation System and as it's powered by its own AAA-sized battery, it won't drain the camera's power.

The unit's Simple Navigation function calculates the direction and distance from the camera's current location to a given point using either information stored on images, or by registering and assigning the destination by uploading location data via a computer. An onboard Electronic Compass combines the information from the GPS and the camera's magnetic sensor, and indicates the aspect of the camera in relation to true north.

Sky watchers will be particularly interested in the Astrotracer feature. This works with the camera's Shake Reduction system to calculate the movement of heavenly bodies using latitude information obtained from the GPS, and the camera's alignment data from its magnetic and acceleration sensors. The camera's image sensor is then shifted in sync with the movement of the tracked points in the sky, resulting in solid images of stars and planets rather than troublesome blurred streaks, even during extended exposures.

The 1.9 x 1.3 x 2.3-inch (48.26 x 33.02 x 58.42 mm) Pentax O-GPS1 is available now for pre-order for US$249.95, and will ship mid-July.