The video sensor provided with the VidiCube runs in full HD (1920*1080) and with a 70° field of view. As such, it allows for a detection of the viewers of up to 10 meters (33 feet).

Alternative cameras, either USB or IP, with higher resolution and/or narrower angle (aka higher focal) can be used that might allow to go up to 30m (90 feet).

Please read this article for more information for the relationship between face detection distance, video resolution and camera angle.