Using Gel Filters in Flash Units

Using a gel filter with your DSLR camera can help you create some special lighting effects, changing the mood of the scene.
Aaron Cobbet / Getty Images

Gel filters, which are transparent pieces of film made of heat-resistant plastic and which are available in multiple colors, can greatly alter the light generated in a flash unit by applying a color to the light.

If you don't want to use in-camera software processing or post-processing, creating cool special effects in your photos is possible with gel filters. People who have DSLR cameras and external flash units, such as Speedlites, will be able to make use of gel filters. A built-in flash on a point and shoot camera cannot use gel filters.

Simple Gel Filter

Most of the time, a gel filter is just a sheet of material that is tinted with a color. Many times, photographers will place Velcro strips on the sides of the flash unit, while also placing the opposite Velcro strips on the ends of the gel filter strip. It's then easy to attach the gel filter to the flash unit, stretching it across the front of the flash.

Improving Light Source

One use for gel filters is to improve the results of flash photographs taken when shooting in fluorescent and incandescent lights. An incandescent gel filter can negate the yellowish tint such photographs often have when the gel filter is combined with setting the digital camera's white balance to incandescent. The same technique works with fluorescent gel filters and a white balance setting of fluorescent.

Using Multiple Filters

Gel filters work very well with remote flash units fired at the same time in the background. For example, you can use one remote flash unit with a red gel filter and another with a green gel filter along with a background wall when shooting an indoor holiday photo. The remote flash units can negate the harsh shadow against the wall from the primary flash mounted on the camera while creating holiday colors at the same time.

Odd Angle Options

Beyond lighting the wall with the gel filters on the flash, consider lighting the floor and shooting the subject from above. With the flashes along the floor, you can create some interesting light patterns and some interesting color combinations. This can be a tricky shot in which to achieve the proper exposure, but it will definitely yield a unique look.

Change the Mood of the Scene

Another option for using a gel filter with your DSLR camera and flash is to attempt to change the mood of the image. Perhaps you want to give your subject the feeling of anger or defiance. Use of a red gel filter can greatly affect the mood of the photograph from the perspective of the viewer.

Simulating a Fireplace

When shooting a family photo in front of the fireplace, having a fire going is a nice touch. If it's the middle of summer and you don't want an actual fire, though, try placing a remote flash unit with a red gel filter in the fireplace with a log or two. As the photo is taken, a red flash from the fireplace can simulate the fire, adding warmth to the photo.

Tap Into Your Creative Side

Finally, get creative with gel filters. You can create some truly unique photos with gel filters. If you have a willing subject, try a few different positions for the remote flash units and try a few different colors of gel filters to help you achieve the best final result.