How to make a real large shape of fire in the middle of a field?

robbie75vr

robbie75vr

Active member
I want to do some shapes ( circles, triangles...) of fire (just the outline) in the middle of a field (nothing flammable on the field, no plants, no grass .. nothing, just mudd.

how can I do that? I need a very visible fire, the shape will be large, about 100/150ft. I also have to be able to turn it on in few seconds and it has to last more than a minute. Maybe fuel and fabric stripes?


Any suggestion welcome
 
150 ft in few sec is very fast, almost an explosion.
So either you need severel ignition point and a remote control, or you need some fast igniter like black powder.
you can do flammable material by using potassium or sodium nitrate (weed killer) diluted in water with sugar, then soaking some material in it (a natural fiber rope like hemp (will burn slowly) or cotton (faster) ) and let dry. this would create a relatively safe material, easy to deploy, to ignite.
all depend the kind of fire you need color, length of flame. by addin magnesium or aluminium powder, salt , you can control light and color.
an easy way would be to "paint" the rope with aluminium or copper spray paint.
you can also mix 2 ropes, a fast one for ignition, and a slow one , impregnated with petrol. for duration.

playing with fire is always dangerous, especially in that case you will handle a lot of flammable material.
possibly you could do this effect in post
 
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Post, miniature. both. Flat mud at 150 ft looks the same as mud at 2 ft. Borrow a hand driptorch from your local volunteer fire people for the miniature, loop the footage to burn for as long as you need.
 
nosys70 said:
150 ft in few sec is very fast, almost an explosion.
So either you need severel ignition point and a remote control, or you need some fast igniter like black powder.
you can do flammable material by using potassium or sodium nitrate (weed killer) diluted in water with sugar, then soaking some material in it (a natural fiber rope like hemp (will burn slowly) or cotton (faster) ) and let dry. this would create a relatively safe material, easy to deploy, to ignite.
all depend the kind of fire you need color, length of flame. by addin magnesium or aluminium powder, salt , you can control light and color.
an easy way would be to "paint" the rope with aluminium or copper spray paint.
you can also mix 2 ropes, a fast one for ignition, and a slow one , impregnated with petrol. for duration.

playing with fire is always dangerous, especially in that case you will handle a lot of flammable material.
possibly you could do this effect in post
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This is of great freat help ! thanks a lot, I would love to do this in cg but I want it very realistic, and I'm not expert in CG, unless you know some relatively easy solution that works in AE.

Post, miniature. both. Flat mud at 150 ft looks the same as mud at 2 ft. Borrow a hand driptorch from your local volunteer fire people for the miniature, loop the footage to burn for as long as you need.
Click to expand...

Thanks rainer for your help but there will be a guys in the middle doing some stunts with a motorbike so I need him to be under the effect of warm light from the fire.
 
This all sounds like an ultra terrible idea. For the love of God either dont do it or have it handled by a professional.
 
Josh Bass said:
This all sounds like an ultra terrible idea. For the love of God either dont do it or have it handled by a professional.
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don't worry we're not so stupid.. :violent5:some 15/20 inch tall fire at 60 ft from a subject is not dangerous unless we're talking about dumb people but we're not.
 
robbie75vr said:
...there will be a guy in the middle doing some stunts with a motorbike so I need him to be under the effect of warm light from the fire.
Click to expand...

I'd plan on doing most of that warm light effect of the fire through lighting.
I'd plan on doing most of the fire effect by perspective. Shoot through/over smaller fire that is further from the talent.
And I agree with Josh Bass. This is something that you want to have a professional on hand for. Some years ago there was a shoot in Canada that was using fireballs next to snowmobilers and snowboarders. Well, the crew had it all set up to be safe and not get the fire near the talent…until it went wrong. I can't recall if it was fatal or just severe third degree burns, but it didn't end well. Things go wrong easily and quickly when you involve stunts or motorcycles or fire. Combine all three? I wouldn't say your three times more likely to have an issue, but at least 100x more likely. Safety first. and second. and third.
 
the talent will be in the middle of a road, the small fire off the road, dont worry guys we're ok, really... there is no danger at all.
 
A small fire turns into a big fire real quick, think about the worst case scenario and how you would deal with that.

I hate to say it but it sounds like you have very little experience with flame effects so that immediately indicates there is a danger. Get people who know what they're doing or you'll pay for it later.
 
RyanT said:
A small fire turns into a big fire real quick, think about the worst case scenario and how you would deal with that.

I hate to say it but it sounds like you have very little experience with flame effects so that immediately indicates there is a danger. Get people who know what they're doing or you'll pay for it later.
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guys guys, let's move out from safety issues please, as I said in this case there is no danger at all.

Thanks
 
OK. Here's a little sxf secret from the past before cgi, environmental and safety concerns: mix calcium acetate (from a chemist or make your own) with petrol or kerosine, it makes a slow burning relatively safe sticky jelly (or unsticky solid, depending how much you use) and you can paint it on what you want to see burning (or you can buy it ready made from fx or pyrotechnics supply places, but it'll cost). But practically no-one does that nowadays. Check out some of the on-line stock flame footage (Google) and overlay that on some of your motorcycle footage and see what you get. You can animate the color cast of the motor cycle footage in say, After Effects to make flicker flame effects. But really, I think you need to ask around for local qualified sfx/vfx people or a pyrotechnician, even if you have to pay them it's going to be cheaper than a tanker load of fuel (unless they want to use a tanker load of fuel, of course).
 
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http://www.cnn.com/2014/02/26/showbiz/slates-for-sarah-elizabeth-jones/

Do you want your production to turn into this? They began their investigation as a homicide and I'm sure they will seek criminal charges against some of the production staff.

http://www.csatf.org/pdf/19FLAMES.pdf

One of the first bullet points.

A responsible person (such as a Special Effects Operator in charge or other qualified individual) shall be designated for the daily handling, placement, safe
use and securing of any open flame devices.
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Notice the word qualified. Are you qualified in any way? Do you have any training or certification to show that? Maybe you have done this many times before and I'm just missing something here...If you don't, you need to get someone who is.

From the sort of questions you're asking I'm going to take a wild guess and say you aren't qualified to make those sort of judgement calls for safety on behalf of your cast and crew. You should hire someone who is and cover yourself appropriately.
 
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I second Ryan. Not every aspect of safe planning is intuitive.

Put another way: if you have to resort to asking on an internet board how to execute a fire effect over a large area, I think that there exists an unacceptable probability that you are not qualified to predictably and safely execute a fire effect over a large area.

I'm not trying to belittle or disrespect you. Part of professional production work is safety culture. It's important.
 
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