Instead, the fill produces a large, milky highlight that is much less objectionable. • LIGHTING RATIOS The term "lighting ratio" is used to describe the difference in intensity between the shadow and highlight side of the face. It is expressed numerically. A 3:1 ratio, for example, means that the highlight side of the face has three units of light falling on it, while the shadow side has only one unit of light falling on it. That's all the lighting ratio means. Ratios are useful because they determine how much local contrast there will be in the portrait. They do not determine the overall contrast of the scene; rather, lighting ratios determine how much contrast you will give to the lighting of the subjects).
(Note: In the descriptions
that follow, the key light refers to the main light source(s). The fill light refers to the source(s) of illumination that fills in the shadows created by the main or key light. In outdoor lighting situations, the key light can either be daylight or artificial light, such as that from an electronic flash or reflector. The fill light outdoors can also be either daylight or flash.) Since lighting ratios reflect the
This is an interesting lighting scheme created by Tibor Imely. The bride is backlit, as if she were being posed in profile. There is very little fill light, which keeps the lighting ratio high, however there is good detail in the dress and in her neck area. This is caused by the soft
difference in intensity between the
nature of the overhead backlight. A background light can be seen illuminating the area
key light and the fill light, the ratio is
behind the bride and a kicker is used from the opposite side and behind the bride to illumi-
an indication of how much shadow
nate the veil.
detail you will have in the final por-
Ratios are determined by meas-
trait. Since the fill light controls the
uring the intensity of the fill light on
the face. The key light, however, only illuminates the highlight side.
degree to which the shadows are
both sides of the face with a light
Determining Lighting Ratios.
illuminated, it is important to keep
meter, then measuring the intensity
There is considerable debate and
the lighting ratio fairly constant. A
of the key-light side of the face only.
confusion over the calculation of
desirable ratio for outdoor group
If the fill light is next to the camera,
lighting ratios. This is principally
portraits in color is 3:1 because it is
it will cast one unit of light on each
because you have two systems at
ideal for average shaped faces.
side (shadow and highlight sides) of
work, one arithmetical and one log-