What cameras do film studios use today? ARRI? Red? Does anyone have some insight into what's actually used today and how to get trained to become a DP or a camera operator?

I found a couple of pics from Ridley Scott's The Maritan behind the scenes production. This camera gear is fucking insane. I can't even figure out where the actual camera is (I'm guessing at the bottom?) And what the hell is all this other stuff?
Anyone wanna share some knowledge?

Also, post some other movie rigs!