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Low budget lightening


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#1 Patrick Barry

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Posted 02 November 2009 - 11:44 AM

Hey all,

We're shooting a project in the next few months and I have two questions.

1) What is a good, low budget method of creating a flash of lightening outside of a window. I had thought of using a few different camera flashes, with different strengths, and shooting them off almost at the same time. I have to do some tests to see how well that would actually work though.

2) Secondly, we have one shot in the film, a locked-down wide shot at dusk, that needs some composite work. On the horizon, we see some storm clouds building up with heat lightening inside, lighting up the clouds. I would rather avoid if possible making the clouds and lightening CG. I was trying to figure out a way to "create" my own clouds and film them for the composite shot.

I did something similar to this in a short film, where we shot a cut-out of the moon, which was backlit, through a fishtank and poured half and half in. Then we filmed it in super slow mo and it gave a great moon-and-clouds-at-night effect which we composited into our film, but this is a little trickier since its day.

Any and all thoughts are appreciated. Thanks.
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#2 David Mullen ASC

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Posted 02 November 2009 - 11:57 AM

Metal shutters (like venetian blinds) on a bright HMI light is one of the simplest ways of creating lightning. It's hard to get the duration of electronic still camera flashes to be long enough or have the right pattern.

Storm clouds rolling in were done in "Close Encounters", "Dragonslayer" and "Raiders of the Lost Ark" and other 80's movies by use of a large tank with an inversion layer of half salt water, half fresh water on top, with an injection of some sort of white paint using needles into select areas. The clouds of white paint stayed above the inversion layer. Very tedious to shoot and every take requires draining the tanks and starting over again, and you need fairly large tanks. I'm not sure exactly how the inversion layer was created -- I think they filled the tank halfway with salt water, then put a sheet of plastic on the surface, then filled it carefully with fresh water, and then carefully pulled the separating sheet out?

You're better off shooting your own plates of real approaching storms, perhaps undercranked to speed up the clouds. Or even time-lapse with a DSLR. That way you can match the lens focal length better to the plate with the actors.
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#3 John Sprung

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Posted 02 November 2009 - 02:53 PM

1) What is a good, low budget method of creating a flash of lightening outside of a window.


The cheapest of all is just to turn the camera off and immediately back on again. As the speed dips, a few frames get heavily overexposed. To be believable, you can't have any bright lights in the room. All the light should come from outside, because this brightens everything. If you're shooting sync sound, do both head and tail sticks, so you can pull up the track at the flash point. (And of course the lightning can't hit on a line.... )




-- J.S.
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#4 Will Earl

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Posted 06 November 2009 - 07:24 AM

This flickr set has a bunch of good photos showing the process of filming a cloud tank. I believe rollers placed in the tank are used to help guide the plastic sheet out of the tank, so it slides horizontally between the two layers.


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#5 Denny Lajeunesse

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Posted 02 December 2009 - 03:51 PM

I think the newer Dataflash or Martin Atomic's can be programmed now a days to simulate lighting. Usually with a few set at different speeds. Might need some tweaking but should be affordable.

A flashy little unit that packs a powerful punch, the Dataflash AF1000 features technical advances that place it in a class by itself. This individually addressable strobe can be used in a variety of settings to simulate lightning or as a continuous illumination source. It features an advanced xenon flash lamp system and multiple ultra high-power flash heads that can be controlled by any DMX source. Regulate rate, duration and intensity remotely with full DMX-512 remote control. Trigger several simultaneously for powerful white light flashes that simulate lightning storms. It’s available in a yoke-mountable non-weatherized or weatherized design to withstand the rigors of touring or demanding performance conditions. Optional accessories include different colored domes, available in clear (standard), red, blue, violet and green.


http://www.highend.c...flashaf1000.asp
http://www.martin.co...?product=atomic

Edited by Denny Lajeunesse, 02 December 2009 - 03:54 PM.

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#6 Frank Barrera

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Posted 02 December 2009 - 11:12 PM

About 10 years ago i worked on a large music video that required lightning effects from multiple locations around a massive stage as the band performed. The Director and DP wanted near constant lighting throughout a 6 minute song. The production rented several high powered lightning strikes but that wasnt enough. So they brought in three of these homemade lighting strikes which were boxes made of wood, plexiglass and tin about 4'X4' with a bunch of large gauge carbon rods bunched on the bottom and the same up top. One end had #2 Entertainment cable attached to it coming from the neutral and the other end had the hot end. I operated one of these monsters by jamming one end into the other and then "riding" the arc for a couple of seconds at a time. this created not just a great lightning effect but also a very loud cracking sound. Unfortunately these things were not designed for the constant use that we wound up requiring from it. Finally my "box" began to melt and then burst into flames. i remember being very upset and concerned for not just my safety but the entire productions as we were indoors. But the senior electricians, seemingly knowing that the situation was under control, just smiled and stood around as i frantically smothered the flames with a sound blanket.

although this is a low budget effect i would never recommend attempting it without a highly experienced electrician involved.

its funny. over the years when ever a lightning effect is required i share that story with production when they inquire about a low budget solution. after hearing the part about flames they never seem to hesitate to cough up the money for a proper lightning strike.

gd luck

f
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#7 David Rakoczy

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Posted 03 December 2009 - 09:00 PM

Lightning Strikes are great.. and easily controllable... the old school method of mashing Carbon Arcs (rods) together in a plexi box deliver a more... 'organic' strike. We used Carbon Arc Strikes on Stan Winston's PUMPKINHEAD. I love the mashed carbon arc method.. but you have to designate a plant just for that as it draws a ton of amps. I don't recommend 'Shutters'.. I have used them and they just don't 'feel' real..(to me). If I had a choice, I would use the carbon rod method any day. There is a sample of Lightning Strikes on my Feature Demo Reel (at the beginning there is an Exterior Night scene using Lightning Strikes.

Another Lightning Thread
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#8 Hal Smith

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Posted 03 December 2009 - 11:03 PM

What's needed for the power supply for the DIY carbon rod lightning effect? AC? DC? Voltage? Current?
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#9 David Rakoczy

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Posted 03 December 2009 - 11:44 PM

220 DC. I remember having a plant dedicated to it (Plunger Arc) and while at craft service you could hear the generator struggle and belch black diesel smoke as it struck. Here is a mini version here

Here is how the roll call went on Pumpkinhead... Camera you ready?... ok... Let's lock it up!... Smoke it up!... Wind!... Leaves!... Lightning!... Camera!... Monster!... ACTION!!!!!!!!..... cut ...... back to one! :lol:
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#10 Matthew Parnell

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Posted 07 December 2009 - 07:27 AM

Just be careful with strobes if you are shooting on Red, the rolling shutter can cause issues. I'd be recomending serious testing to make sure you don't get half frame strobing.

Also be aware of what rules are in place regarding strobing for your project. You don't want to be causing epilectic fits.

I have to agree Martin Atomics are very good for this kind of work if you are on a budget. They aren't a clunkly backyard solution either. They can be Either operated by an electric using a detonator(the atomics hand held dmx controller) or off a console. They can also be linked so you can use a number of them together. For example on a previous show I did we used two through windows then one bounced into foamcore for fill.
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#11 JD Hartman

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Posted 11 December 2009 - 09:17 PM

Can't be totally certain, but I would think the "mashed carbon" lightning is producted from low voltage high current DC, maybe 32VDC, much in the way a carbon arc heating torch operates. So you would need a largish motor driven DC welder. Something like this: http://cgi.ebay.com/...=item414b2d35e0

At auctions, garage, estate, farm, tag sales they often go cheap.
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#12 John Sprung

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Posted 12 December 2009 - 01:01 AM

Traditional carbon arcs, IIRC, ran on 120 Volts DC. But there was a big series resistor called a "grid" in series with the arc. This stabilized it and cut the voltage across the electrodes down except during the initial strike. They were also a nice source of heat on cold night exteriors.




-- J.S.
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#13 Josh Campbell

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Posted 31 January 2010 - 06:05 PM

This flickr set has a bunch of good photos showing the process of filming a cloud tank. I believe rollers placed in the tank are used to help guide the plastic sheet out of the tank, so it slides horizontally between the two layers.

That was really helpful! Thanks, but I just want to know the formula for the ink. ;)
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