Light Source: The Power of Three-point Lighting

Everybody has to start somewhere. Camera operators learn the basic shots and movements and graduate to more difficult and exciting work. Audio operators begin with a basic knowledge of microphones and recording devices and move up into the creation of soundscapes. Lighting designers, called "directors of photography" or DPs in the film world, learn the art of lighting by perfecting the most basic yet important tenet in light design: three-point lighting.

In this article, we will look at the various components of three-point lighting. We will discuss different lighting instrument options and describe how to use them. Finally we will explain how you put it all together to create lighting that will give your videos a professional look.

To begin, you need to ask the director (which might very well be yourself), some very important questions. First, where will the camera be in relation to the subject? Is the shot going to be outdoors or indoors? If outdoors, how will the sun affect the shot? If indoors, is there a window or door that has sunlight filtering through it? Will the subject be moving? Is it day or night? What mood are you trying to achieve? While this may seem to be a fairly extensive list of questions, it is only the beginning. Once you have the answers to all of these questions, you are ready to begin designing the lighting scheme. You begin by deciding how to set up the components of three-point lighting: the key light, fill light and back light.

The Key Light
The key light is the main light. It is usually the most intense and direct light shining on your subject. For basic lighting such as that used for interviews, imagine your subject in the middle of a clock face on the floor with 12:00 behind the subject and the camcorder at 6:00. You would place the key light beside the camera at about the 4:30 position. Elevate to an angle of 35 to 45 degrees above the subject. This placement creates some shadows on the face, giving it a three-dimensional shape. The height is enough to keep it out of the subject's eyes, yet not so high as to create dark shadows under the eyes. For those subjects with glasses, lower the key light slightly to eliminate the shadow across the eyes caused by the frame of the glasses. Be careful of glare reflected off the glasses. Typically, you would use a softlight to soften the lines and texture of the subject's face. If you require a more dramatic look, you would select a harder, smaller light.

When designing for a dramatic story, look at the surrounding set and try to duplicate the lighting that would usually exist. If the scene takes place in a living room at night, set the key light to approximate the look of a floor lamp, table lamp or ceiling light. If the scene is a daylight scene in an office, the key light might be the sunlight coming through a window or a desk lamp or top light.

Whatever the situation, the key light is the starting point from which the rest of the light design evolves.

Once you figure what kind of key light you need and where you want to put it, the next step is to determine the style and placement of the fill light.

The Fill Light
The primary purpose of the fill light is to fill in the shadows, thus its name. The fill light is typically larger, softer and more diffused than the key light. While the key light gets all of the notice, the fill light is more critical to establish the mood, time of day, and quality of light in a scene. Because of this, the fill light is perhaps the most important of the three lights used in basic lighting.

In a basic setup such as an interview, you would place the fill light on the side of the camera opposite the key light at about the 8:00 position. It is elevated at an angle of 20 to 30 degrees above the subject. This placement fills in the side of the face away from the key and reduces or fills in the shadows created by the key. The brighter the fill light, the fewer shadows and the less dramatic the scene will be.

This difference in brightness between the key light and fill light is called high-key and low-key lighting. In high-key lighting, the fill is very strong and the contrast between the fill side and the key side is reduced. This is typically how you would light news, most interviews, talk shows and game shows. In low-key lighting, the fill light is very dim, which creates a high contrast between the key and the fill lights. This lighting is very dramatic. You would use this type of light for movies, dramatic interviews and other dramatic scenes. It is the fill light that determines how dramatic a scene will be.

To distinguish between an indoor daylight scene and night scene, you would again turn to the fill light. For daylight scenes, you would use a strong fill light and reduce the contrast between the fill light and the key light. For night scenes, you may decide to use no fill at all.

The lighting instruments used to create fill light are also the most fun and creative. Besides diffused lamp light, you can use a host of other lighting accessories. A white piece of foamcore or white posterboard makes a wonderful bounce card for fill light. Place the white bounce card so the light from the key light bounces from the card to the subject's face. You will be surprised at the amount of light you can bounce off the white surface. This is very useful when doing interviews in the field and you need to carry a minimum amount of equipment or have very little power available. For a more intense reflected fill light, you can use a variety of silver reflectors. If you want to add a little color to the scene, use a gold reflector or a colored bounce card.

After you have established the fill needed to create the appropriate look for the subject, you have one more light to deal with--the backlight.

The Back Light
The back light's primary function is to separate the subject from the background. By lighting the back of the subject's head and shoulders, the resulting rim of light helps establish that the subject is located some distance from the background.

For the basic three-point lighting set-up, you would place the back light at a higher angle than the key light, behind the subject. Make sure that the back light does not shine on the lens of your camera. As with the key light, the back light can be hard or soft depending on the look you want to achieve. Soft light is more difficult to control and will tend to cause problems with lens flare.

As with the fill light, the amount of back light will determine the dramatics or glamour of a scene. The more intense the back light, the more glamorous and dramatic the subject. However, you must determine the amount of back light needed by noting the hair color of the subject. Blonde-haired people require less back light than brown-haired people do. A good rule of thumb is the lighter the hair (or head in the case of a bald man) the less back light that is needed.

Fine Tuning
Once you determine the lighting needs of your scene and set up the key, back and fill lights, you are almost ready to shoot. Always look at your scene through a viewfinder and on a color monitor if possible. You can fix weird shadows with fill light or changes in the key light placement. You can also fix reflections off glasses or bald heads by slightly moving the key or fill lights. Remember that light moves in a straight line and bounces at opposite angles. If you see a strange reflection, determine which light source it is coming from by placing your hand in front of the reflection and looking for the shadow, or turning off one light at a time until the glare is gone. The shadow will be exactly in line with the culprit light source.

The last thing to keep in mind while setting up your three-point lighting is that this is just the beginning. Use your imagination, and adapt your lighting setup to your surroundings. Recreate the light that you would see in real situations. By controlling the light, you are controlling the mood, time of day and dramatic intensity of a scene. This is an awesome power in the hands of a creative videographer. Use this power to your advantage to create professional quality productions.