Home of Professional Cinematography since 1996
style="margin-bottom: 0"> Fire Effects
Published : 15th April 2008
>I'm involved in shooting a short film in a couple of days, it's a night shoot and there's a scene with a kind of quasi-religious ceremony around a bonfire, candles, chanting, sacrifice etc we're shooting on HDV we have a secret recipe for Gels for a 'spooky' moonlight colour ( sorry, i could tell you but then I'd have to sacrifice you! )
>I was wondering if anyone out there had any suggestions for :
>A/ flicker, I have 2 in line dimmer units and have in the past used a hand held flag ( piece of black wrap) randomly wobbled in front of a redhead to give flicker, this worked the best with the right operator.
>Any technique out there that would allow for a convincing flicker without tieing up a person all night flickering, would be helpful (crew are a bit thin on the ground) or maybe we just drop the flicker and rely on the fire/candles as practicals to create the effect of fire. as a bad flicker effect may be worse than no flicker
>B/ gel colour, for fire, I was gonna put maybe a couple, maybe 1 and a half CT orange gels on the Redhead, white balanced for tungsten
>C/ The bonfire, a real fire is the easiest, but continuity and Quantity of wood are both issues I wondered about a flame bar. I've been told it's really simple, but don't want to mess with something I'm unfamiliar with. I have the remains of a gas barbeque, Regulator etc, that could be cannibalized for parts is there a sensible, safe way of keeping the fire burning without getting a truckload of timber? and without risking barbequing our 12 extras there's very little budget, we have 3 Blondes a bunch of redheads and some little reporter lights to work with not to mention 300 of those little tea light candles to twinkle in the background
>Any suggestions appreciated
class="style8">>> long hose, gas tap will be manned at all times
>> And will only use the flame as a source for light if it can be used safely,
>Regarding using gas around talent for drama work...
>Do you need synch sound? If you do you may want to check with whoever is doing the flame bars: they are often noisy and bad for sound.
>Might not be a deal breaker, but worth consideration.
>David Perrault, CSC
>My favorite night effect is half blue and white flame green. It's a very silvery moonlight.
>Didn't see this in time, and I've posted this particular fire effect in the past, but what the hell--I'll post it again.
>Build a big source, about the size of your fire, or at least 4'x4'. Light it just in the center with a light gelled red, or red-ish, and then, with another dimmable and gellable light, light the whole surface with a warmer light (at least full CTO, if not more). Flicker the warm non-red light. The red light acts the way coals do, always providing a red base light that kicks in when the flames are low and casts sharper shadows because it's a smaller source. The warm non-red light acts like the flames, shifting the color away from red to warm and casting softer shadows.
>Enhance the effect by using three lights: small area red, larger area peach, largest area CTO or double CTO. Flicker the last two. The peach probably wants to flicker slower than the CTO.
>This came from sitting in front of a fireplace and just looking at it. After 20-something years of looking at similar fireplaces.
Director of Photography
Film | Hidef | Video
San Jose, CA, USA
>You could try putting a number of normal 60/120W light bulbs (say 8/10 depends how bright you want it) on a piece of plywood. If you wire 4 or 6 of them each individually as required in series with a starter (the one used in fluorescent tubes) you should get some random flicker. you'll burn out the starters eventually but they are relatively cheap to replace. That should keep some hands free hopefully, and get closer to the colour temperature you're looking for.
>any technique out there that would allow for a convincing flicker without tieing up a person all night flickering, would be helpful (crew are a bit thin on the ground)
>Werner Van Peppen
Quantel, Newbury, UK
>>Gold Mylar...for a broad flickering source use 4'x8' gold mylar (or >>better, two 4'x8' frames.) You can bang whatever tungsten sources you >>need into it, ...
Perhaps point a fan at the mylar to induce flickering effect. Another approach might be to shoot a filtered source through strips of darker gel blown by a fan.
10 Squared Corp.
>There is nothing better then a real flame bar. Nothing comes close.
>If you must create it with lights large filaments on dimmers are best-- (5ks and 10ks dimmed down) as they take more time to cool, thus creating a more realistic effect. If I recall correctly dances with wolves has a decent example in a teepee with 1k nooks.
>Phil Ball wrote:
class="style8">>>there's very little budget, we have 3 Blondes a bunch of redheads and >>some little reporter lights to work with not to mention 300 of those little >>tea light candles to twinkle in the background
>Had a shoot earlier this year three people and a campfire, Bounced a 2K into a gryflon, and positioned a crew member to dance the flag between the light and the gryff. Yep, it does take away a crew member, but it is fairly simple once they get the hang of it.
>I'd expect to see more effect in the background actually, with a big bonfire that ought to act as multiple sources so the light on the background will noticeably change more than that on the people close to the fire.
New York Based Cinematographer
class="style8">>>do people use a flame bar to actually light the talent?
>I have done this a lot, Easter 2008 for Mutant Chronicles
>Totally agree about safety, us a SFX guy.
Geoff Boyle FBKS
22 Exeter Road
tel: +44 (0)207 748 3238
mobile: +44 (0)7831 562877
class="style8">>> I've built a flame bar now,
>I've worked with a number of different types of flame bar... depending on what your feeding pressure is, you can drill holes (much like a gas ring burner) you can use a hacksaw or cut-off wheel to cut little slashes in the pipe, much like many furnace burners, or you can cut longitudinal slots in the pipe which give more sheet-like flame bits.
>You can also use flexible copper tubing or aluminum tubing and shape it into curves or even spirals.
>Do make sure that you have some distance of pipe or hose between the propane tank with its shut-off and the flame bar so you can get to the valve and shut it off and/or regulate it safely.
Obviously all these suggestions include the implicit "use an experienced Special Effects Technician - fire is potentially dangerous to people and property and should be used on set with qualified personnel."
LA based VFX DP/Supervisor
class="style8">>>I'd expect to see more effect in the background actually, with a big >>bonfire that ought to act as multiple sources so the light on the >>background will noticeably change more than that on the people close >>to the fire.
>That's a very interesting point and I can see how it may make the fluctuations more realistic
>Thanks for all the feedback,
>I've built a flame bar now, basically a copper pipe with an in-line tap to regulate the flame size and a few holes in the end of the pipe works great
>This is mainly to give us a convenient "easily turn of and on-able" source of fire for the practical sacrificial fire is there a design of flame bar that works best?
>Suck it and see?
>We tried spotted down, orange gelled, redhead pointing vertically up bouncing of a hand held silver backed poly board ( standard UK building insulation) this hits trace frame positioned near the actor
>Kind of works
>Maybe the red pointing away from the talent with the dangly cloth or strips of gel hanging from the barn doors and hitting the 4x4' silver poly with a little fan pointing at the gel, to agitate the dangly bits ( although with recent weather, probably not needed!)
Could even put the fan through my dimmer...?
>Do people use a flame bar to actually light the talent?
if we did this we'd need another...
>GO GET A FIRE EXTIGUISHER NOW!! sorry for shouting, but I haven't heard anything about safety yet.
>Okay, I've kept my nose out of this since I'm not a gaffer, but now since you've gone and built yourself a flame bar, especially since you already said that you are uncomfortable with it, I've got to speak up.
>Being an FX guy, I wanted to suggest that you use a flame bar in the first place. However, it would have been irresponsible of me since I am aware that you don't have the budget to do it safely.
>I can't give you any tips on how to do it because of liability, but I can tell you that you should seek professional help. If you can't find one of us to help you, at least talk to someone at a local propane company to set you up with the proper gear.
>GO GET A FIRE EXTIGUISHER NOW!
Location FX Inc.
>I'm sorry, extiNguisher!
Sorry about the word wrap issue too.
Location FX Inc.
>I Totally agree about safety, I already went and got a fire extinguisher, in fact i got it before the gas will have fire extinguishers, bucket of water and bucket of sand standing by, I'm trying to get a fire blanket as well all talent will be briefed, long hose, gas tap will be manned at all times
>And will only use the flame as a source for light if it can be used safely, if it's too windy it may not light constantly enough anyway the main reason for using gas is to make the bonfire more controllable, which will make it safer than using firewood
>so any possibility of a problem and there will be no hesitation in my not using it I promise the only sacrificial murder in the production will be fictional!
>Good point! we'll test it out tonight!
>The shoot keeps getting put back so we have time to check this
>Many thanks to all of you for your kind help and suggestions, some off the list , some on we shot it last night and it went well, without incident ( well, a runner singed his finger with a candle)
>We only used the flame bar for the central bonfire, it worked well, with damp firewood it didn't catch or smoke too much, looked perfect the scene was lit with our trusty 2K twinkling through the dappled trees, the gas fire, and a ring of about 400 practical tea lights with an occasional red head gelled for moonlight or firelight further notes to add firstly to the safety issue, lighting :
>*** by the time you find where the gas is, coming from between the logs it has a tendency to go 'WOOF' and take your eyebrows off!
>i lit it with a hand held gas blowtorch at arms length moved in gradually, it always went ' WOOF' and it always made people jump we didn't use the gas flame for the close-ups a couple of sparks tried to build a rig with dangling cloth agitated by a fan between the redhead and a polyboard, but never quite got it to work. So we went for a silver polyboard delicately fluttered with one hand and held firm with the other as with most of these things less is more in the fluttering action that silver poly, is my latest favourite thing the best gel recipe we used to match the colour of fire light seemed to be one and a half Colour temperature orange Gels when the spark/runner wasn't quite so delicate with the fluttering, and it looked more like the (UK) RAC had arrived, we locked down the poly board and wibbled a little flag between the lamp and the poly
>We have a secret recipe for Gels for a 'spooky' moonlight colour (believe me someone's tried it before and posted it on this list)
>Why post for suggestions if you wont share your ideas?
>Is this not the point of CML
>Unless I've missed a joke.
>I've got a secret recipe too. But I'll share it…
>Take the following :
>(1) Arri 18k
(1) expendable electrician
>Combine ingredients logically, add energy, elevate and shake lightly with an occasional gust to agitate electrician.
Continue till daylight and repeat at sundown. Best results are obtained by adding generous amounts of chilled water droplets and lowering temperature to just above freezing.
>Yield: (1) electrician with a story to tell on the next shoot.- OR - (1) former electrician.
>Jared "I'm an FX guy now" Petticrew
Location FX Inc.
>I take your point about me being a bit cheeky asking for advice then not sharing the recipe for moonlight gels
>I did though promise a friend not to pass on the colour of the gels when he let me in on the secret, A promise is a promise! It gives a greenish colour to the light, looks a bit eerie like you said, it has probably been done plenty of times before
>A little slow on replying to this, but your technique for fire light sounds very effective.
>White flame green and half blue.
I have used white flame green and quarter blue before, as a moonlight