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.