How to film laser light shows?

I am planning a trip to the Black Hills and there is a nightly laser light show at Crazy Horse monument. What should I use for film speed/camera settings? I will be using a Pentax 645.

I've never done it so I'm going to take some guesses here... :)

It'll be dark (obviously) so you'll have long shutter speeds if you want to expose for the ambient light at all. If there are lights on the monument, you could base your exposure on that so it shows up, but you'll need a spot meter to do it. I'd probably set it to be one stop underexposed so it shows up a little dark.

Another guess - it's going to be a little like shooting fireworks. Again, I don't really know. But with laser shows, you probably want faster shutter speeds to show some detail rather than just a big blur. Taking your exposure based on the monument, you'd probably need fast film and a fast lens to get anything. The difference between ISO400 and ISO800 might not be enough to be worth the tradeoff of using ISO800 (more grainy).

I think it's one of those situations where you try to figure out what you want to do, then do your best when you get there. It might take several visits to get the right exposure and a nice clear sky. This is how I approach stuff like this, hope it helps.