Anyone know thier light-guns?

From what I understand, lightguns used to work off detecting the point of light on a cathode-ray tube, but modern lightguns work off panels that you stick to the side of the screen. I’d like to know:

  • How big can the screen be? Can it wourk on a 6’ x 4’6" projection screen?
  • Is the gun basically the mouse?Sorry: this is a question about hardware rather than software, but this felt like the best place for it.