
When to use CTO gels?
Use a CTO gel (color temperature orange) for balancing flash with the color temperature of tungsten lighting or sunset, that way the color temperature of your flash matches the ambient light resulting in a natural blend. This helps when you want a wedding couple you placed in the sunset, for example, to have a balanced warm feeling in their skin tones as opposed to a pale look you might be risking without using a gel.

When to use CTB gels?
Use a CTB gel (color temperature blue) to increase the color temperature of your flash and to make it look cooler. During overcast weather, for example, the color temperature from your flash could read as a little too warm. In that instance adding a CTB gel would allow the flash and the ambient light to be better balanced.

When to use a green gel?
Use a green gel for balancing flash light with fluorescent light. Shooting in fluorescent light environments can be tricky; add to that any ambient window light coming in and your image risks a strong magenta influence. This is where a green gel comes into its own – placed onto your light the green gel brings balance to your image again.

When to use color effect gels?
Add creative color effect gels to boost your creativity and to shape light in color. They help you make the most of any lighting situation where you want to use color as an extra creative element to the image. Create golden hour light, simulate a cool club light or create interesting highlights on the face of your subject.
How to create natural light with flash
Adam Angelides shows how to work with the B1 and OCF Gels to create a natural looking light with flash