[Cousin Eddie]

Various ways to do this.

If there are multiple reels, as soon as you finish the first reel, start the second reel and start reel #1 on a second screen.

They can also reflect off mirrors onto multiple screens from a single projection booth.

Of course if it's a digital projection, stream the feed to multiple projectors at the same time.

[macamadamia]

Thanks for the explanations.