We’d all like to have a professional lighting technician, and an unlimited budget to get the perfect lighting setup for the perfect scene. But the reality is, most of us are lucky to have 2 or 3 lights in our arsenal. Knowing how to control your lights can help maximize their potential. In this two part segment we talk about the properties of light, and using gels to control the color, intensity, quality, and color temperature of your light sources. Learning to use lighting tools properly will help you create a great looking scene, even if you’ve got limited resources.
We'd all like to have a professional lighting technician, and an unlimited budget to get the perfect lighting setup for the perfect scene. But the reality is, most of us are lucky to have 2 or 3 lights in our arsenal. Knowing how to control your lights can help maximize their potential.
In this two part segment we talk about the properties of light, and using gels to control the color, intensity, quality, and color temperature of your light sources. Learning to use lighting tools properly will help you create a great looking scene, even if you've got limited resources.
Knowing a little bit about how light works can help you understand how using gels will affect your lights. Light has three primary colors, red, green, and blue. Light is additive by nature, which means that combining the 3 primary colors will produce white light. While mixing two colors together, will produce a secondary color that is common between the two primary colors. Combining green and red results in yellow, blue and green creates cyan, and blue and red makes magenta. A gel filter works by absorbing specific portion of the light. For instance, a magenta filter will absorb all the green light, and allow red and blue to pass through. The red and blue combine so that we see magenta. This is important to understand, because using colored gels to create an effect can have interesting results with the colors in your scene, whether it's the paint color on the wall, or the wardrobe your talent wears. Let's go back to our three light example. A white object will reflect red, green, and blue equally, and we perceive the combination of those colors as white, so the object looks white. However, an object that is pure red will only reflect back the red portion of the light spectrum, absorbing all the green and blue. So if you shine a pure blue light or a pure green light on a red object, no color reflects back and it will appear black. So you have to be careful with any color you add into your scene, and make sure it's not going to negatively impact how things looks on camera.
Now that you understand a little bit about how light and gels can affect your scene, let's talk about attaching them to your lights. One of the most common ways to attach a gel is to use classic wooden clothes-pins, also known as C-47-s, and clip the sheet to the barn doors of your light. Other types of lights may have attachable frames to hold the gel. Just remember, you never want to place the gel directly over an open faced light, as it's sure to melt almost immediately. There are four main types of gels. Effects gels filter the color of a light source to create an effect. Neutral density gels to reduce the intensity of a light source. Diffusion changes the qualities of a light. And color correction gels alter the color temperature of a light source. In part one of this segment, we're going to cover effects gels, neutral density gels, and diffusion. Color correction gels will be covered in part two. Effects gels, or as some people call them, party gels are available in numerous shades. These can add color to a specific portion of a scene such as a background, or even to give the entire scene a specific mood. Colors in the amber range can create a warm feeling, colors in the blue range can create a cold feeling, and colors in the pink range can be used to breathe life into skin tones.
Let's use this interview setup as an example. We have warm amber gel over our background light to give a warm feeling. Now let's switch out the amber for a blue gel. You can see the mood of the scene feels much colder. Now let's add a pink gel to the light on our subject. You can see how it warms up the skin tones. Controlling the intensity of your light is just as important as controlling the color. A neutral density gel is used to reduce the intensity of the light source without affecting its color temperature. ND filters typically come in a range that reduces the light output from one-half to four stops of light. ND filters are a great way to make one light with the same bulb much more versatile. While dimmers may seem like an easy way to achieve the same task, it should be noted that
dimming a light will lower the color temperature about 10k per volt when dimming. This can definitely create some strange mixed temperatures in your scene.
While Neutral density gels control the intensity of a light, diffusion will help control the quality of the light. Diffusion helps to control the size, shape, and intensity of your light source. It can soften hard edges, reduce the hotspot from a light, and change the contrast ratio of the highlights and shadows when lighting a subject. The thicker the diffusion, the softer your light source will be. Keep in mind that diffusion can shift the color temperature of your lights. The most common types of diffusion include spun, frost, white, rolux, silk and grid cloth. Let's take a look at this setup with a hard light producing a shadow, and see how different types of diffusion affect it. Spun diffusion uses non-woven material to create a light diffusion that softens the hard edge of a light, while leaving the beam shape intact. Frost diffusion uses polyester material to create medium diffusion that spreads the beam while maintaining the center. White diffusion provides a medium to heavy diffusion that spreads the beam evenly and eliminates the beam center and edge with greatly reduced shadows. Rolux diffusion is a heavy diffuser that virtually eliminates shadows. This can be used to blend multiple lighting sources to appear as one. Silk diffusion is a medium diffuser that directs the light to help reduce the cone shaped scalloping effect from a light source. Grid Cloth is reinforced diffusion similar to silk that is ideal for larger applications. If you're using diffusion on a light that has spot-flood control, and you want to get the maximum light output from it, you'll want to adjust the control further toward flood so that the light fills the diffusion material fully, without spilling outside of it.
Great lighting is one of the cornerstones of producing high quality projects. Knowing how to control the color, intensity, and quality of your light can help your light kit shine. In part two of this segment, we'll show you how to use color correction gels to get proper color temperature balance in your scene. Thanks for Watching.