Hi Nick, Matt, greetings :)
The 240FPS you're going to get from an overcranked Sony won't show you
anything but mellow flowing arcs. We tried that with a Rx100MkV (it's what
the Captain's Blog series is shot on) and even with our big FS-100. 240
Frames is great for slow-mo at human speeds, but not this stuff.
Even at 17kFPS we can't get much of what we want. We were trying for
stepped leaders, Project Thumper discharges, and Project Groucho's Marx gap
going off.
Our next step will be getting a serious high speed camera (up in the
250,000FPS and faster range). But those come with 6-digit pricetags and
it's a long, long way down on the budgetary wishlist.
I support anyone who wants to try this, when it comes to shooting arcs in
high speed I certainly wish you the best of luck trying to figure out the
lighting. We've never really figured out how to do it well.
I think that just means we need to screw around with it more though. :)