The so-called "blue-c" is a novel three sided immersive projection system, which has been especially designed to support telecollaborative teamwork [4]. Therefore, special projection screens are used, which can be switched to a transparent state electrically. The user is captured with sixteen cameras in total, standing outside of the projection room. These images are then processed to create a 3D representation of the user, which can be projected in a second installation. The whole installation has been engineered and implemented at the ETH Zurich [9]. A special active stereo projection system, based on LCD projectors with additional shutters proved to work very well at a very competing price. The paper describes the background of the decisions made and the problems that had to be overcome.