Some photography lighting features reflectors for light diffusion.
Every form of art produces a subjective representation of its subject. Even highly technical art forms such as photography have subjective elements. Knowing light your subject carefully can help you control the appearance of the image, subjectively determining what to show and what not to show. Using the basic studio lighting setup as a starting point, you can make adjustments as needed to create your optimal photo shoot lighting.
Key Light
No matter how you modify a lighting setup, you must use the first and most essential light: the key light. This light provides the main illumination of the subject and can serve as the basis or "key" for the placement of all subsequent lights. Place this light pointing at the subject at approximately 45 degrees to the left or right of the camera position. Raise the key light so that it points down at the image at approximately 45 degrees. You may choose to adjust both these angles according to the needs of your shoot.
Fill Light
The fill light lives up to its name by "filling" the intense shadows created by the key light. Sometimes intense shadows serve the needs of your shoot, but generally some amount of fill helps make the image more completely visible. Point the fill light at the same angle as the key light from the opposite side of the camera. You may reduce the intensity of the fill light by moving the light further away from the subject, or you may use a lower-wattage lighting instrument. A reflector in place of a fill light can provide a light, adjustable fill for less than the cost of a lighting instrument.
Back Light
The back light gets its name because it lights the subject from the back. Placement of this light can cause problems with excess light if it points directly into the camera lens. Set this light directly behind the subject and at a lower angle pointing up at the subject, if needed. The back light creates a thin line of light behind the subject known as an "incident highlight." Position the back light until this line appears without flooding the lens with direct light.
Hair Light
When lighting a portrait or certain types of objects, you may wish to use a variation on the back light known as the hair light. Like the back light, the hair light shines light from behind the subject but from a high angle down onto the subject. The hair light should light the top of the subject's hair, leaving the face in shadow so as to not interfere with the key and fill lights. Do not use the hair light when photographing a bald person because it can produce an intense reflection.
Background Light
The background light, like the other lights in your setup, does exactly what its name implies. It lights the background of your subject, helping the subject to stand out by defining its outline. Point the background light at the background of your image so the center of the light hits the background directly behind the subject. You may wish to shine the light from above, below or at an angle from the side. A background light works best when it communicates the feeling of the environment of the subject, whether ordinary and evenly lit, bright or dark and mysterious.
Tags: back light, behind subject, fill light, hair light, light from
