I know City Theatrical sells those fancy DMX shutters that turn Video Black to actual black, but they're a wee but expensive. But its a pretty simple system I think I can work out on my own. I'm even open to a mechanical system (like pulling ropes). The projector is fairly large, (bigger than your average, but not a Christie or anything, just InFocus). It is on a ceiling mount on a 10 foot or so ceiling, about 10 feet from the lighting desk. I've considered motors, this is cumbersome. Steppers would be too complex, and some sort of actuator is too slow. I think I can work something up, just wondering if anyone else has taken on a similar project.