Gels
A "gel" is a sheet of special see-through plastic that can be used to change the color of light coming out of an instrument.
There are thousands of gel options that are beyond the scope of this lesson, but a few are worth mentioning.
1) Color correction gels make certain studio lights (balanced for 3,200 degrees) put out the same color of light as sunlight. As you might expect, these gels are blue-ish.
2) Amber colored gels are used to give subjects a bit of "healthy tan."
3) Blue gels create a nighttime feel. In movies and television, night scenes are often just as bright as day scenes. The only difference is night scenes have more blue light. That's because human eyes are designed to see blue better in low light conditions. So people unconsciously perceive blue=night. Lighting designers take advantage of this when they light nighttime scenes.
At the left, an orange gel is clamped onto the barn doors of a portable spot. The gel gives the scene below an orange hue, as you might expect. Professional lighting directors generally don't throw color on an entire scene, however. Usually the gel is directed onto certain areas for a more nuanced effect.
