Tutorial: Improvised Strip Light

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This was a very quick experiment with an improvised ‘strip light’. For those who don’t know, a strip light is a…

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…type of softbox that is very long and narrow. A ‘strip’ in other words. It’s a rather esoteric type of light modifier, mostly used in the studio rather than on location. It has a couple of properties differentiating it from a regular softbox. Because of its long narrow shape, it creates relatively soft light along the long axis, and relatively hard light along the thin axis. So if you used one of these in the upright position to shoot a portrait, you’d have hard shadows falling across the width of the face, but soft shadows under the chin and nose. If you suspend one over the subject’s head, you have even, soft lighting from left to right, but a hard ‘butterfly’ style nose shadow.

Another feature is that it allows you to light a long object (say the side of a person) evenly, without also throwing a lot of light around the rest of the room. Best used in close though, otherwise the long-and-thin effect is negated.

There’s a nice little video here that shows you how to build a DIY strip light using fluorescent work lights. “Build” is probably too strong a word, as it’s really more of a case of “buy it and clamp it to a light stand”. Still, pretty useful and I might try it one day. But this isn’t a light I need very often…heck, haven’t needed it ever, as far as I know! No point in spending hundreds of dollars on a ‘pro’ version that I’ll use a couple of times per year—and probably use it only that much because I felt the need to get my money’s worth!

But I got to thinking about strip lights using regular strobes. At first I thought about using some plastic gutter, and firing a strobe from one end. I’d put some diffusion material over the front, and it’d turn into a strip light. It would be brighter at the strobe end, with the light falling off toward the other end. Not a bad thing sometimes, as you might want a little fall off toward the feet of your subject. But before I went out to the hardware store to buy some gutter material, I thought a little further. What about a simple V-card, closed up so that the opening was only a few inches, and then firing a strobe down the ‘crease’? Seemed like it was worth a shot. And it had the added benefit that I didn’t have to go any further than the garage.

A V-card is simply two pieces of board (usually foam board, usually white), hinged together with tape or something else. When folded in a V, it stands on its own and can be used as a reflector or a gobo/flag, depending on the color or purpose. I have a 4 ft high one made of 1.5″ wide foam insulation. The two panels making up the ‘V’ are about 2 feet wide each. At one time I used this on the beach as a light modifier, bouncing one or more strobes into it. But the spill on the ground (not to mention the wind-catching capability) eventually made me opt for umbrellas and such.

So that’s what I tried, and it seems to work as intended. The lead shot above is the result of my experiment. Note my ‘subject’ (my almost-three-year-old son) has pretty hard shadows in the creases of his forehead and down the length of his nose. But the shadows under his neck (camera left) are barely there. There’s a little fall off toward the ground, but not as much as you’d expect. The light spill is pretty well contained. Even on the couch behind him! He was about four feet away from the opening of the V-card, by the way. This was shot during daylight in our living room, with overcast skies outside. f/8 and 1/250 shutter speed if I recall correctly. His proximity to the light source allowed me to lose almost all the ambient and see just what the flash was doing. You’ll notice a little fill on the camera-right side of his face. I don’t think this was ambient. I think it was probably a little bounce from the far wall camera-right, which is a beige color.

Below is a picture of the V-card itself, with the strobe firing. Rather than taking the time to set up a light stand (and to keep my kids busy on a ‘daddy daycare day’), I had my six year old son hold the strobe over the top. I’ve got the little ‘catchlight’ reflector card on the strobe extended, to keep direct light from the strobe firing forward. You can just barely see the writing on it.

Note that the fall off—at least viewing the ‘strip light’ like this—seems pretty significant. But in actual use it didn’t seem to make much different. More subtle than I would have expected. I had the strobe set to zoom, probably the 85mm setting. This was an attempt to make the lit area of the V-card to extend as long as possible, for more even light. I could have bumped the strobe’s zoom up to the max, but I don’t know if it would have made any difference. Also, a little bit of diffusion material (like some shear white cloth) across the top half of the V-card would help even things out even further.

My version of a strip light would be hard to extend overhead in a horizontal direction, which makes the fluorescent version more appealing. The fall off would also maybe not make as much sense in a horizontal position…I don’t know. But overhead, one could use this as an interesting ‘beauty dish’ light…subjects’ noses that weren’t perfect might tend to hide their flaws, while still having a strong shadow underneath. Might be worth investing in some work lights to try it out!

P.S. I have no idea why my youngest felt the need to model with two tooth brushes in his hands. But it was very important to him that they make the shot!

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