Thanks for your concerns, SourceChild.

We did the show back in Sept. It went really well. I'm pretty sure the projectors were 21k. Plenty bright for the live audience, but a little dim on camera. It would have been nice to have them doubled stacked.

As I mentioned earlier, our projection screen was actually a white scrim curtain with fullness. Because of that, the edges were undetectable. Seriously, I had trouble finding them sometimes...and I knew they were there!

As far as alignment goes...catalyst's "curved screen test" works great. I just had the projectionist center each projector and fill the screen with the excess shooting beyond the screen. Then I tweaked the control points until everything lined up. Piece of cake.