This stereoscopic video is created using two cameras side-by-side to capture the left and right eye images. The data is then linked to a LAPTOP live to analyse the convergence and seperation. Shooting with two cameras might complicates the production and post-production process but speciallise equipment cameras, rigs and connected laptop enables users to see interactively which minimise errors.
Further Info: http://www.youtube.com/watch?v=O_g-up7Eh8c