The Essentials of Three-point Lighting
Three-point lighting is the basic starting point for film and video. This method utilizes three light sources focused on the subject from different angles. Mastering this technique is the foundation for more advanced lighting strategies. The goal of three-point lighting is to properly light the subject while also separating the subject from the background. This approach is the basis for portrait lighting, but it can be used in other situations as well.
The key is generally your most intense light and is placed 15–45 degrees to the side of your subject. The main purpose of the key is to wrap the face in the appropriate quality of light based on the subject’s features and the story you want to tell. Using a broad, soft source of light like that produced by a soft box or fluorescent fixture such as a Kino Flo is a popular choice when shooting interviews. If you have the room, a bounce key can be even more pleasing: The light is bounced off a flat surface or card and is reflected onto the subject’s face to create soft light.
Ideally, you’ll determine essential information about your subject before you light the shot. You’ll want to identify important factors like skin tone and texture, hair color (or lack thereof), and wardrobe, so you can light accordingly. You’ll also need to know the “color palette” of your subject so you can achieve the right lighting balance.
The fill is your secondary light and is generally placed on the opposite side of the key. Its purpose is to fill in the shadows cast by the key light. To what degree you utilize your fill light is a matter of taste. Ideally, you’ll use a small lighting fixture or bounce the light off a card or flat surface. Often, you can use some reflected light off your key to produce some fill.
Selective use of fill light can have considerable impact on the mood you create. Try varying the amount of light used and look at your monitor or viewfinder after you make adjustments. The amount of falloff you use for the key (which creates shadows or transition) can really change a viewer’s reaction to your subject’s face. This light can significantly affect the mood of the portrait you are shooting.
You’ll also need to experiment with the quality of fill light. When creating fill, you’ll almost always choose to reflect the lights off an indirect surface. Whichever surface you choose can make a big difference. Some are shiny and specular, whereas others just soften a source like butter. A shiny surface will not give you the same feel as a matte finish. Use the way different skin tones take the light as a reference point. You can also use a gold reflector to warm up your light. Just be sure to consider how reflections can affect the mood of the shot.
Backlight is the third element in three-point lighting. Its purpose is to highlight the edges of your subject, separating it from the background, which creates more of a three-dimensional look. The backlight is identical to the hair light you might use in a portrait setup. Placement of the backlight is usually behind and above your subject, but it can depend on the shape and quality of the human (or other) head.
Sometimes the backlight works best close to the floor or off to the side (it is then called a kicker). The purpose is still the same, which is to create a multidimensional feel to draw the viewer’s attention to a subject. The quality of this light can be as varied as the key and fill. A bald head often looks best with a bounced backlight, whereas a subject with a full head of hair can usually benefit from more of a direct treatment. Always look at your monitor to gauge what’s best.