D-I-Y Light Blockers: Gobos, Barn Doors, Snoots and Grids
Learn what’s available. Try a homemade version first. Use it a lot? Then consider professional versions.
One way to control light during a photo shoot is to block it. Some things and some areas need to be kept dark. The most practical way to do this is with black paper and cardboard.
Adjustable flash coverage
Many of us already have a flash that adjusts to the angle the lens sees. If we have full manual control, we may be able to set the flash for a long lens (narrow angle of coverage) and then actually use a much shorter lens. This gives the flash a slight spotlight effect.
The gobo is a black card that goes between the light and anything else we don’t want to light. We can use gobos with any level of sophistication we want. Lone photographers often handhold a gobo in front of their light as far as their arms can reach. Hollywood directors of lighting (DLs or LDs), with bigger budgets, attach the gobo to a separate stand (and use a half-dozen names for different sizes and shapes of gobos).
More sophisticated gobos with holes can create moody lighting. With a little patience and a sharp knife, you can make your own. Gobos with holes are called cookies (short for cucoloris, with several spelling variations). The photo below shows a homemade gobo, which makes the light from the flash appear to be sunlight streaming through window blinds. Also below is a commercially made wooden gobo to simulate, say, light passing through tree leaves. Certainly it’s sturdier than the cardboard version, but you can make something similar yourself and spend your extra money on other photographic equipment.
The photo below shows a slatted homemade cardboard gobo in use. Depending on the angle and the intensity of the light passing through the gobo, it can look like light coming through a window with blinds or can simply create an interesting pattern on a background. In this case, the gobo was clamped in place on a stand. The studio was darkened because the background was lit with a continuous tungsten light source. This light isn’t very bright, so a long exposure was needed. (How long an exposure? This one was 2 seconds. But the determination comes from how strong the continuous light source is and how bright we want the background to be.) A flash was positioned slightly off-axis camera right in a medium-sized softbox. The flash was used to light the man. Even though this was a long exposure, the man is sharp because he was lit only by the flash.
A barn door is a special type of gobo that attaches directly to the light; we need no additional stands or hands to support these devices. Barn doors swing open and closed to control the spread of the beam. This sounds like a good idea until we realize that there’s no way to move a barn door closer or farther from the light, and that’s a big loss of control. Sometimes, though, we don’t need precise control. Then we prefer the barn door because it is the simplest and least cumbersome way to block light.
We can make a barn door simply by taping a black card to the flash and bending it as much as we need to restrict the beam. If we find ourselves using barn doors frequently, then we buy a commercially manufactured barn door that has better durability and precision. Usually, one barn door is enough, but for uses such as background lights, we may put them on all four sides of the flash.
Snoots and grids
Snoots and grids go over lights with the purpose of restricting the light’s spread. Using these can be a huge step for a novice who wants more dramatic lighting. As with the barn door, we can make snoots and grids for pennies. Only if you find yourself using them over and over might you consider buying one. (Also, know that we must have a commercially manufactured metal grid and probably an auxiliary fan for studio strobes to avoid overheating.) The photo on the following page shows the basic supplies we used, which not everyone will have on hand: cardboard, straws, and tape. We’ll also need scissors, a ruler, and pretty much any glue—all of which we already have. We can measure each side of the flash or we can wrap a piece of paper around the flash, pressing so that we can see where the edges are.
Making a Grid:
Cut a piece of cardboard to go around your flash, adding about 3⁄8 inch to create a flap, which you’ll eventually use to seal the ends together. It should be about 31⁄4 inches deep, enough to hold a handful of short soda straws plus an empty section to slip over the flash.
Score the cardboard lightly to help it bend around a rectangular flash. Cut the straws into 1⁄2- to 3⁄4-inch lengths. This doesn’t mean the straws should be different lengths—they should all be the same—but you may decide to make a deeper or shallower grid later for a wider or narrower spot effect. Bend the scored cardboard so that the widest part is on the table and you’ve got the ends sticking up. If you put a book on either side, it will free your hands and keep the sides vertical. Then start gluing the straws to that widest portion of the cardboard. You want the straws to line up at the outer edge of the cardboard.
Keep going until the space is filled and you can then fold the top down and seal the box by gluing the flap and wrapping it over. Then spray everything, inside and out, with flat black paint. For added sturdiness, wrap the sides of the grid with black gaffer tape. It should fit snugly enough as is, but if you like, you could make the box a little deeper and affix Velcro so it can attach to your flash (especially if you already have Velcro on the flash to hold barn doors).
The grid seems to focus the light, but it really doesn’t. It simply blocks light going in directions we don’t want. Depending on the area we want to light, we may have to buy a more powerful flash to compensate.
Making a snoot
A snoot does exactly the same job as a grid. It’s much less effective than a grid, but we can make one in a few seconds with black paper and tape. (We should try to always have black paper handy. It is so often useful for needs we might not have anticipated.)
Basically it is a small opening through which light will pass, thereby restricting the spread of light. Below is an image made using a homemade snoot constructed from a cereal box. Isn’t creativity great?
Excerpted from Focus on Lighting Photographs by Fil Hunter & Robin Reid ©2011 Elsevier Inc. All Rights Reserved