When mounted on the supported PENTAX cameras, the O-GPS2 provides the advanced ASTROTRACER function, which couples the unit with the camera's SR (Shake Reduction) system for the effortless tracing and photographing of celestial bodies. The unit calculates the movement of stars and other objects using the latitude obtained from the location data and the camera's alignment data (horizontal and vertical inclinations and direction) obtained from the electronic compass and acceleration sensors. It then shifts the camera's image sensor in synchronization with the movement of these objects. This means that all celestial bodies are captured as solid points rather than blurry streaks, even during extended exposures. It also simplifies the astronomical photography setup, since it requires only a tripod and eliminates the need for an additional accessory such as an equatorial telescope.