When I first heard the term “gel,” I envisioned a gooey substance that was smeared over some clear glass plate that covered the flash. Not exactly! Gels are a heat-resistant material, similar to plastic, placed over lights to change their color. Gels come in large sheets and hundreds of colors.
I cut my gel sheets down to fit over my studio strobes and TTL flashes. Some TTL flashes come with gels precut and ready to be used on the flash. Rosco (www.rosco.com) makes a variety of gels and offers a Roscolux swatchbook of all their colors.
The gel sheets in this swatchbook fit perfectly on a TTL flash head and cost next to nothing at major camera stores. Use gaffer tape when attaching the gels to your flash. Gaffer tape won’t leave a sticky residue when you take it off and still sticks well when your flash gets hot after repeated firing.
What can gels do for your photography? They’re used in a number of different ways, from correcting the color temperature of a light source to adding surreal effects to a flash shot. I think of gels as another creative tool to use in my photography, and you don’t have to follow any rules in using them. Following are just a few ideas on using gels. Experiment, because in the end you can use gels any way you want.
Most people assume you put a gel on your flash. When you need to correct the color temperature of a light in a room, you actually can put the gels right over the light source itself using gaffer tape. Here’s an example. I once photographed a room interior with mixed light sources. The room had window light, table lamps and fluorescent lighting—three different temperature light sources. Since changing my camera white balance only would help match one of these light sources, I decided to gel the fluorescent room lights and stick with a daylight white balance.
I added magenta-colored gels over the fluorescent lights, which turned them from ugly green to clean white in color.
I let the table lamps in the room stay as they were, which resulted in a warm yellow color coming from the household bulbs. The end result was a room with clean white light accented with warm tones from the table lamps. The only challenge was getting the exposure right for all the light sources. Dimmer switches work great for interior shooting.
One of my favorite portrait techniques is to add an orange gel to my flash with my white balance set to incandescent. Daylight turns blue with an incandescent white balance, and your flash also will be blue, since flash is close to a daylight white balance. The trick is to add an orange gel to your flash, which counters the incandescent white balance, resulting in a neutral daylight balance to anything the flash illuminates. This is a great technique to add mood and tension to an image and works especially well with cloudy skies.
There are other examples of counter-filtration flash. Sometimes, shooting indoors, the room is illuminated by fluorescent lights. To fix this problem, add a green gel to your flash to match the color output of the overhead fluorescent lights. Set your white balance to fluorescent, and you’re ready to go. All the light in your images should be white since the light sources are color-corrected to fluorescent. The Rosco swatchbook will show you the gel you need to color-correct the light source you have to balance. Take a shot, and if the color looks slightly off, try another tone of gel to better color-correct your light source.
If color correction sounds a little too precise for your tastes, try picking any gel you like and adding it to your flash. My favorite task when I’m using TTL flash is thumbing through the colors in my gel swatchbook, picking a color I like, and gaffer-taping it to my flash. No science involved. Maybe you’re going for a high-tech look, and adding red to a science lab gives your image the right look.
I once taught a photo workshop in the Czech Republic where we photographed a famous bone chapel. The walls of this chapel are decorated with the bones of 40,000 parishioners, definitely a moody place! I wanted to enhance the mysterious nature of this chapel, so I added blue and red gels to my flashes to get the right effect.
Take the laundromat image. My idea was to photograph a woman in a laundromat, but with a wild, crazy look. To capture the right atmosphere, I needed to add lots of color. I used six TTL flashes in the dryers with blue gels, two larger flashes on the model using red gels and another large flash in the background using a green gel. All the flashes were triggered using radio slaves. Wow! Some color combinations work better than others. Creating warm light on a cool blue background is very effective.
I often flash the background with deep blue gels, and flash my subject with a subtle orange gel. The warm tone really advances off the blue back-ground and produces a striking effect. Complementary color combinations work well, too. Try red/green, yellow/purple and blue/orange. When complementary colors are side by side, each hue is more vibrant.
You don’t need to limit your use of gels to flash. One of my favorite activities when I’m on the road is light painting in my hotel room using my gel swatchbook. I’ll admit my wife thinks I’m a little crazy: “Hello, this is my husband Tom. He hides in his hotel room at night and shines a red flashlight on the walls.”
But it’s really fun! I use a small Streamlight stylus flashlight (www.streamlight-flashlights.com) and shine it through a gel at my subject. Place your camera on a tripod and attach a locking cable release. Set your exposure to “Bulb,” aperture around ƒ/5.6, ISO 200, and focus on your subject. Make sure the room is totally dark, lock open the shutter (using the locking cable release), and pulse the flashlight through different-colored gels onto your subject.
Experiment to see how much light the scene needs; your exposure can range from 30 seconds to several minutes. I often use two or three different colors in a shot. Trust me, this is addictive, and you’ll never leave your hotel room.
The next time you’re thinking about creating an image, don’t forget to include gels in the equation. Sometimes adding a little color is just what a shot needs.
Tom Bol is a freelance editorial and commercial photographer based in Colorado. To see more of his photography, visit www.tombolphoto.com.