There are so many names for light that one could easily get lost. We have a Main source, which some prefer to call the Key, Modeling or even the Contrast Light. Then there is a Fill source, which is also referred to as Supporting or Base. There are background , Hair, and Accent which have a multitude of names such as Rim, Kicker, Back or Pencil. But what do these source styles really do and how do we use them?
The Main is normally the strong or broad light source such as the sun, or in a studio can be ambient if you have a window source (preferably emanating from the north), but more likely is a parabolic strobe or flood source. Most photographers, including myself, use some sort of a light modifier to disperse or soften the light. The closer the source is to the subject the more diffused (softer shadows) it becomes, conversely the further away the more focused or pinpoint it becomes (harder shadows). I advise never directly pointing the source at your subject, yet by using its edge/penumbra because it is softer and even.
Main sources are typically positioned somewhere around 45° relative to the subject as the vertex and the camera, which is positioned on a ray that initiates from the subject/vertex. Main sources of illumination determine the direction of shadows and defines the subject by creating roundness and an illusion of depth while adding highlight s to the face(s) of your subject.
The Fill should be a non-direction and non-spectacular broad source which originates from behind the camera. It is almost always diffused by using an umbrella, soft-box, or is bounced and, unless permanently mounted is placed as close to the camera as possible, as mentioned in part 1 of this series, preferably behind the camera at a point high enough to avoid creating a second catch spectacular highlight in the eyes of your subject. Some photographers prefer to use a reflector instead of a parabolic source to fill the shadows. No matter what source you choose, remember, the Fill source is the key to your light ratio and should create enough light so your shadows are not under exposed.
A Background Light is generally a small, low powered, source that is placed between the subject and the background. Depending on the effect you desire, it is generally placed close to the subject anywhere between the waist and shoulders. You can point/aim it down to create a vignette over the top of the head, or, move it fairly close to the back ground and point the head downward to create an area of brightness over the shoulders and have a sharp shadow fall above the shoulders. Illuminating the background allows you to create another dimension or plane while creating separation.
Typically placed above and behind the subject and is designed to add definition to the subject’s hair while creating accents and separation from the background.
(Rim, Kicker, Back or Pencil)
Usually placed on the same side of the 180° as the main light source, creating an obtuse angle, and is generally on the same plane or perpendicular to the subject’s head. The ‘accent’ is used to add separation, strength, texture and creates depth. You can use more than one accent source if you so choose.
You can learn more about lighting portraits in a studio session by signing up for hands-on one on one private mentoring sessions. Call (215) 887-1248 and ask for Jeff.