I am completely new to projections, we are attempting to use them in our spring production. I have a 18X30 blue sharkstooth scrim draped upstage. We are planing on trying rear projection, to avoid actors crossing the projector path. We will have three separate projectors, which will be mounted above and behind the scrim. We have tested them, and know that they are bright enough to do what we want, but now my problem is figuring out how to control them. We are planning on projecting moving and still images of the sky: day, night, sunrise, sunset, and a storm with lightning. I have access to both a macbook pro, and a new Imac, and we are planning on renting the Qlab license. How do I link the three projectors, to control them? I'm playing with the demo version of Qlab, but since it isn't the video license I can't seem to figure out what I'd need to do. Oh, and as always. On a "limited" budget.