(dramatic orchestral music)

It begins.

Hi, I'm Mike Seymore, an Effects Guide for Wired.

This week we will look at cataclysmic annihilation via ipads.

As you might expect from the title in the new biblical epic

Noah, filmmakers needed quite a lot of rain and water.

In fact, as it turns out, in terms of manhandling

water and rain over a crowd of people,

it's one of the largest of it's type ever done.

As Oscar-winning special effects Bird Dalton told us

the old adage for filming special effects

is front light snow, and back light rain.

This is because unless rain is back lit,

it's very hard to read on camera.

The team had to produce rain effects

to cover an outdoor set about the size of two football

fields and they quickly realized they needed to do this

by shooting night for day.

Since if they were to shoot during the day,

they would have the sun constantly moving

and they'd never consistently be able to back light

the rain, but lighting up a couple of football fields

with a torrential deluge isn't that simple.

Their solution was to build a huge light and rain rig

on three 300 ton cranes.

Hanging from each of the cranes was a vast set

of rain bars, each of which were about 100 feet

by 40 feet wide, and on top of those were placed

massive balloon space lights.

You know those really big nozzles that firemen

have on the end of their firehoses?

Well, they had about 100 of them up in the air.

The system rained down about 5,000 gallons a minute

from these huge arrays using two different types

of rain sprinklers.

One called a goose drowner which is the big one

that produces big droplets

and much smaller mist sprinklers

that were set up in between.

There were 3,050 of 12 inch pipe that was run

from 100,000 gallon tanks through giant manifolds

backed up by two huge 12 inch pumps

that managed to provide 150 per side over the hundreds

of feet of pipe hanging up in the air over the heads

of about 500 screaming extras.

And all of this was controlled by the ipads.

The ipads allowed the team

to always correctly light the rain.

Each individual rain head has it's own solenoid

so if the team wants to white out the background,

they can turn on and run just the mist heads at the back.

If they want pouring rain, they can run those really big

goose drowners and of course it's easy to turn everything on

but it's just as easy to isolate one area and keep it dry

or from the power of this custom ipads app.

Each night the team raised the rig up,

they used about 100,000 to 200,000 gallons of water,

which is well over a million gallons, or the equivalent

of about two Olympic-sized swimming pools

dumped on the side over the 15 nights of shooting.

In the end, the whole scene had a massive water simulation

digitally added by ILN to complete the sequence.

Well, don't forget to subscribe

for more behind the scenes action.

I'm Mike Seymore for Wired.

(pulsing orchestral music)