What is a Flash Gel
Q. So what exactly is a flash gel?
A. A flash gel is anything that you put over your light source to change the color of your light from its native color to something else.
Q. Why would I want to use it?
A. A flash gel will add color to your photos. With color you can add mood to a scene, depth to a portrait, or boldness to a product. Color adds impact, short and sweet. With color you can take photos to a whole different level. In some cases you can use a flash gel to stop down light output. This is helpful if your light source is emitting too much light on its lowest setting, with a Neutral Density flash gel you can make the light less bright.
Q. What types of photos can benefit from a flash gel?
A. Any photo that has a subject that you would light can benefit from a flash gel. For instance a head shot of a person, or a still life scene. Even a landscape can make a good candidate for a flash gel. Maybe you would like to emphasize a color in your foreground, or maybe you would like to light paint with a flashlight and add a flash gel to it. Just look at Kevin Adams site HERE to see what can be done with a flash gel and flash light.
Q. What else are is a flash gel used for?
A. A flash gel can be used to balance the light in your scene and the light that is falling on your subject. In this case you would use what is called a color temperature flash gel which is either CTB (blue) or CTO (orange). Speedlites are day light balanced, which means the temperature they shoot at is around 5500k or mid day light. A sunset is around 3200k, which means that the light from the sun will look much warmer in comparison to the light of your flash hitting your subject if you were to use them at the same time. To balance the light you would need to add a color temperature flash gel. The intensity of the color (blue or orange) is measured in stops. A full stop is maximum color, they also come in 1/2 and 1/4 stop variations, which is, you guessed it, 1/2 and 1/4 of maximum orange or blue. CTB (Color Temperature Blue) is used to take your 5500k flash to a higher kelvin to match cooler light. CTO (Color Temperature Orange) is used to take your 5500k flash to a lower kelvin to match warmer light.
For more reading on gels and how to use them creatively I have included a fantastic post from Felix Barjou where he gives a great overview and some examples. In his tutorial he uses the Rosco Photo Filter Kit which you can buy HERE Check it out the article from Felix below.
PHOTO BY Felix Barjou Photography