from the page at the Jewish Museum, Prague:
"a live feed from the Robert Guttmann Gallery at the Jewish Museum in Prague. The gallery is currently running Michael Bielický’s installation This Year in Jerusalem, for which purpose it is equipped with a special device to track movement (a motion capture tracking system).
The system works on the basis of four lamps that emit infrared rays whose reflections off the bodies of visitors to the gallery are recorded by special cameras. This data is transferred to the system’s center, which then generates an image according to set parameters. The image is a double, or avatar, of each visitor, a three-dimensional model composed of voxels (3D pixels). When someone moves in the designated area his figure and movement are captured and immediately transmitted into the image projected on the screen in front of him.
This image is provided by a web camera located at the Western Wall (the Wailing Wall; Hebrew: ha-Kotel ha-Ma’aravi) in Jerusalem and streamed in real time via a high-speed Internet connection into the Robert Guttmann Gallery for the entire length of the installation, thereby offering visitors to the gallery in Prague a unique opportunity to find themselves in Jerusalem without having to overcome any geographical distance between the two cities, or cross any boundaries whatsoever.
The web camera located in the gallery enables you to view this revolution in travel in real time and in a virtual space."