Lighting with fire

[Linda Moro]

hi guys, in the next few days I will shoot a short film with a scene with a fire in open space.  I need some advice on artificial lights, in particular I need them to be space-saving, with a portable battery (not a generator) and to recreate the effect of fire. Let me know your advices!

[Stephen Sanchez]

I would go for rgbww panels, like aputure nova. Fire is very low in CCT so you'll want a light that can go that far. Also, Astera Titan tube lights have a pixel tech that makes for a dynamic dancing fire effect.

I've always ran AC, so you'll have to find your light's runtime on a brick battery and compare the brick's Watt-hours to your portable battery's watt-hours. Batteries-only is tough because there is no safety net, so I would make sure you had either several extra batts, or an inverter genny as a backup.

[Robert Hart]

If your fire is a wood fire which is in the shot, my personal preference would be to replicate a fire which has coaled down to a glow and would be more controllable.

Add some variously sized scrunched up chunks of alfoil into cold charcoals or maybe matte-painted stones with few small lamps wrapped with red gel inside the charcoal/foil mix.

With careful teasing you may then achieve hotspots of coloured light in the darker coals. Your other lamps lighting your character(s) may need to be connected to the small lamps inside the coals so that all lights can be made to vary or flicker together. 

You could try covering a gas ring or burner with small rocks and lighting that up. You might control your other lights with something as simple as a human trembling a leafy branch in front of the light. 

Please heed better advice than mine which may emerge here.

[Stuart Brereton]

I've just finished a long show in Saudi Arabia, which was set in biblical times. Consequently, we lit a lot with fire at night. The SFX department had a variety of fire gags, all fed from propane gas tanks, which made them very controllable. The issue as a DP is being able to expose for people's faces, while also trying to keep some color and saturation in the flames themselves. Shooting wide open on a fast lens at 800 asa means that the flames will just show as white, so you have to build in your own sources, so that you can have faces exposed at a decent level. I was exposing at around f2.8 - f4 at 800 asa, with faces underexposed by 1.5 stops. That was enough to hold the warm yellow of the flames.

Although occasionally I used nothing but firelight to light with, most of the time we were using additional sources to key the actors with. Initially, I was using 2' & 4' Astera tubes to mimic fire effects, and we were also using Aputure BC7 globes inside of the lanterns the actors were holding. I was never happy with the Asteras, and eventually we switched to using little Aputure MC4 LED bricks set to their fire effect. For longer throws, and larger areas we used Skypanel S30s on beaverboards.

Real fire is around 2200K, but we never went that low with our lamps. When you head that far into the red end of the spectrum, the color becomes basically monochromatic, and when combined with underexposure, it can get very muddy and indistinct. I generally ran all our lamps at 2800K which was enough to give a warm glow to skin tones and to create a little color contrast with the colder moonlight tones we were creating.

[Samuel Berger]

On 11/14/2022 at 7:03 AM, Stuart Brereton said:

I've just finished a long show in Saudi Arabia, which was set in biblical times.

And I bet you ruined all that by shooting on a Sony.