The still below depicts a movie effect explosion tripped by a thumb-activated detonation device.
To create the explosion, special effects wizards hung a 13,000-lb. steel plate by a crane. With the push of a thumb, the plate dropped, crushing the military vehicle.
“What they’ll do in the movie is, they will literally take that plate, frame by frame, out, and what you’ll see is the result of what the plate did,” says mechanical special effects specialist Mike Edmonson, who’s been in the industry 34 years. Edmonson, licensed by the federal government and the state of California as a pyrotechnician, clarifies that the scope of the job is not just pyrotechnics. “The scope of our job is basically to create the elements: wind, snow, rain, fog, smoke, dust, fire, plus explosives. It often takes us into the world of electronics, pneumatics, hydraulics, working with motors, and just about anything really.”
Imagine controlling the elements with the trip of a thumb.
Typically, Edmonson says, the control is a thumb push-button. “That push-button could either go hooked to a battery and hooked to our line for a single event. Or we could use what they call a clunker box, which steps. When you press a button you can put it on auto(matic) or semi-auto. If auto, you can set the speed so if you’ve got, say, a machine gun run down a wall or on a floor, you press the button and the machine will step through 20, 30, 40, 100 hits. And so you have all these individual hits tied to this box, but you still have the (one) push-button.”
I ask him, has it always been a thumb button?
“Pretty much,” he says. “It’s a standard way of setting things off — of starting things and stopping things. It’s just so common.”