What Firelight and Windows Have in Common
Firelight and window light have a lot in common. They both require multiple light sources to look convincing. Here are my favorite tricks for reproducing both.
I first learned the “strips of multicolored gels waved in front of a light” firelight trick in film school, and I never found it very convincing. I don’t get a lot of opportunities to use flame bars, and I know there are ways to emulate firelight using multiple china balls with different gels on them. My favorite technique came about by simply staring into a fireplace for a while.
Fires are really two light sources combined. A small source, at the base of the fire, is created by smoldering red coals, while the flames create a much larger source. From careful observation I noticed that the coals are a constant source of light and the flicker comes entirely from the flames.
To emulate this I lit a 4′x4′ bounce card like this:
I lit the bottom of the bounce card with red light and the entire card with warm light. The warm light was controlled by a dimmer or flicker generator. When the warm light was low or off the red “coals” created a very red ambient base light that cast sharper shadows because it lit only a small part of the bounce card. When the warm light reached the top of the flicker cycle the firelight changed color from red to orange, and it cast softer shadows because the entire bounce card was the source. This is exactly what a fire in a fireplace does.
One method is to light the bottom of the card red all the way across. This makes coals light softer as the base of the fire is now the same horizontal size as the firelight overall. To make the coal shadows harder, do this:
Spot the red light into the bottom of the card. Now the coals light is much harder as it’s a much smaller source, so it will cast harder shadows.
Also, by aiming the red light low on the card, shadows on walls leap up and down depending on which source is dominant. When the red light was on shadows fell high on the wall because the source was so low. When the warm light was full on the shadows fell lower on the wall and were softer because the warm light used the full size of the bounce card, making the warm light source higher and bigger.
You don’t need a large bounce card to do this. I recently shot a spot looking into a restaurant kitchen, where I faked firelight by putting a narrow 1′x4′ piece of showcard below the counter. We spotted one red light into the center of the card and then filled the rest of the card with a warm light that flickered. The effect worked perfectly.
What fascinates me about this trick is that I’m using two overlapping sources to create the effect. I started looking around for other places to use this trick and I stumbled across window light.
At one point I lived in a house whose interior was painted white, and while walking down a hall one day I noticed that a 6′ stretch of the hallway was blue on the bottom and golden brown on the top. When I stood at that spot in the hallway looked toward the light source I found myself staring at a sunlit wooden fence, and when I laid on the floor and looked out the same window I saw blue sky.
Looking straight out the window I saw a sunlit wooden fence, which explained why the bounce light hitting the middle and upper part of the hallway was golden brown. When I crouched down…
…I saw blue sky, which explained why the bottom of the hallway was blue.
I’m rarely able to be this adventurous when lighting through windows because you really need the proper set or location to pull this off. Still, I’ve often wondered how it would look if I lit a room for sunset using this method:
Put a bounce source outside a medium-sized window and light the top warm, like a setting sun, and the top blue, like skylight. Where the two sources overlap they should be roughly neutral, but the top part of the room will be warm and the bottom cool, and the transition should be very soft and subtle. Another slightly less subtle way to do this might be to light the entire bounce source blue and then put a warmly-gelled fresnel light in the center of it. If the “sun” is dimmed way down so that it’s just slightly brighter than the sky you should end up with a very subtle and beautiful sunset look.
After my hallway experience I started looking at window light a lot more carefully. Windows can be thought of as apertures, and indeed this is how the camera obscura works. A window projects the image of whatever is outside of it into the room, and the size of the window works roughly the same way apertures do: lots of big windows result in multiple soft overlapping images that all wash together, but a smaller window more accurately reproduces the view outside the window.
For example, if one side of a room with a 4′x4′ window is beige and the other side is green, the odds are pretty good that if you stand in the green light and look out the window you’ll see sunlit leaves, while standing in the beige light shows you the side of a distant sunlit building.
This kind of thing comes in handy when lighting, say, a big white room. Somehow you have to make this room interesting, but it’s pretty challenging to make white walls look attractive. If there are a couple of medium-sized windows then you can put some bounce cards outside, set them at different heights and cover them with different color gels, and make the room look as if it’s actually being lit by light bouncing off exterior buildings and plants. The combined light of the sources is probably semi-soft so it looks reasonably good on people, and the multiple soft shadows of different colors and heights emulate what actually happens in a room that’s lit by bounced sunlight.
Sometimes the fastest way to light a set is to know how light would act if the set were an actual location. The best way to learn this is just to be aware of your surroundings. Lighting tips surround you in your daily life.
About the Author
Director of photography Art Adams knew he wanted to look through cameras for a living at the age of 12. After spending his teenage years shooting short films on 8mm film he ventured to Los Angeles where he earned a degree in film production and then worked on feature films, TV series, commercials and music videos as a camera assistant, operator, and DP.
Art now lives in his native San Francisco Bay Area where he shoots commercials, visual effects, virals, web banners, mobile, interactive and special venue projects. He is a regular consultant to, and trainer for, DSC Labs, and has periodically consulted for Sony, Arri, Element Labs, PRG, Aastro and Cineo Lighting. His writing has appeared in HD Video Pro, American Cinematographer, Australian Cinematographer, Camera Operator Magazine and ProVideo Coalition. He is a current member of SMPTE and the International Cinematographers Guild, and a past active member of the SOC.
Director of Photography