Lighting for a portrait is more than just illumination for proper exposure's sake. Portrait lighting defines, sculpts and flatters the subject along with adding depth and dimension to the image. Portrait lighting does not have to be a complicated process; most portrait lighting falls into three distinct categories---broad side, short side and butterfly lighting. These techniques can be accomplished with a minimum of equipment and alteration; they are quick to set up and simple to understand. Using these lighting techniques will create the foundation for more artistic and dramatic lighting setups later.
Broad Side Lighting
Broad side lighting is a technique that lights the side of the model nearest to the camera. This style of lighting de-emphasizes facial features and makes narrow faces appear broader.
To accomplish this style of lighting, set the main light at a 45-degree angle to the subject and turn the subject's face toward the light. Place the fill light or flash unit at a 90-degree angle to the subject, taking care this light source is well diffused. A reflector may be placed at a 45-degree angle to the subject opposite the main light. Using this will soften the contrast of the image and is strictly optional. Finally, placing a background light between the subject and the background creates the illusion of depth.
Short Side Lighting
Short side lighting is the opposite of broad side lighting in that it illuminates the side of the model that faces away from the camera. This style of lighting works to add angles to rounder faces and is flattering to subjects that have broad features. It emphasizes, rather than hides, facial contours.
Switching from broad side to short side lighting is simple as it merely requires adjusting the model's position. The main light should remain at a 45-degree angle to the model while the model is positioned facing away from the light. A reflector may be used on the opposite side of the main light to soften contrast. A fill light or flash is placed at a 90-degree angle to the subject, again taking care this is diffused well. Finally, the background light placed behind the subject separates subject from background.
Butterfly-style lighting is a high key, high contrast, dramatic look and is often used for glamor-style photographs. This style draws the most emphasis to facial features and is recommended for well proportioned subjects who have an oval shaped face.
To achieve butterfly lighting, place the main light directly in front of the subject at a 90-degree angle. The light should be raised above the subject to create a shadow directly beneath the subject's nose. This technique can be used in combination with either fill lights placed at a 45-degree angle to the subject or reflectors to bounce light back towards the subject.
A variation on butterfly lighting is Rembrandt lighting, which is a combination of short side and butterfly lighting. In Rembrandt lighting, the main light is positioned at a 45-degree angle to the model, and the model is turned away from the light. The main light is raised to create dramatic shadows on the side of the face turned away from the camera.
Types of Lights
This article talks about three different types of light. The main light is the primary light source in the photograph. It will have the most power, the setting of which will depend on the photographer's meter readings. The fill light is used to soften the contrast of the image and is set at a lower power than the main light. This light can be a flash unit or a modeling light. Finally, a background light is a low light source used to illuminate the background, adding depth and dimension behind the subject. These three lights can be improvised using photoflood bulbs (available at a photography supply store for a few dollars) of various wattages, which is an inexpensive way to create a studio lighting setup.