Studio Flash Explained
Simple Lighting Setups

Simple Lighting Setups
While individual approaches to lighting are advocated, there are certain techniques commonly used that have passed the test of time. These “standard” simple setups are particularly ubiquitous in portrait photography.

There are four basic light techniques that are usually mixed to light the scene. By name, they are the Key Light, the Fill Light, the Background Light and the Back Light.

Key Light
The key light or “main light” is normally placed in such a position that it is, visually, the predominant source of light. It is commonly placed somewhat at an angle to one side and slightly above the subject – rarely head on. This off-angle placement encourages shadows to form, shadows that define the shape of the subject.

Any degree of diffusion that suits the objective may be used on the key light. In general, if the subject is young and fashionable and you are after a dramatic presentation, small source sizes will bring more drama. On the other hand, if you desire a softer, more romantic feel, larger sources are often in order. But keep in mind, a large light source effectively becomes smaller and smaller as it is moved away from the subject. So very soft lighting dictates placing lights close in.

The old standby umbrella, either the “bounce” type or the “shoot through” type, makes an excellent large source diffuser for these purposes, as do softboxes. Remember though, the closer the diffuser is to the subject, the greater the effective amount of diffusion and light “wrap around.” Don’t be afraid to place a shoot-through umbrella or softbox extremely close to the subject - even a few inches, to get the effect you’re after. Remembering that light falls off according to the square of the light to subject distance (according to the inverse square law), you will find that close light placements result in rather strong gradients of intensity across the subject. On a single subject, this effect can be a point of interest and can create a very personal sort of “low key” mood. With groups of people, more distant lighting is indicated in order to achieve more uniform illumination of all subjects.

When making mental judgments of the effectiveness of the main lighting, as viewed with modeling lamps, one must remember that the tonal range that can be captured and printed is much narrower than what you can see with your eyes. What appears to the eye as a nice contrast of light and shadow is apt to come out as overexposed highlights and formless dark shadows. Therefore, when previewing the scene under modeling lamps, look for the visual effect of light and shadow, but think in terms of a significant increase in contrast in the final pictures.

Fill Light
This is where the second basic light source, the fill light, comes into play. In most cases, the fill light will be quite diffused, possibly using a large white umbrella or softbox, or bounced off an adjacent neutral color wall or bounce reflector. Its historic purpose is to introduce sufficient light from the side opposite the key light to lighten the shadows to pleasing (and printable) proportions. It will usually be less powerful than the key light so as to not appear as a primary source of perceived illumination. The term “fill” means what is implied – to fill in shadows.

Background Light
In most portraiture, the subject will be placed sufficiently away from the background to preclude strong subject shadows from being cast on the background. With front lights at an angle towards and slightly above the subject, the shadows will fall below and to the sides. In any event, the front lights (key and fill) will not cause much illumination of the background. Without some form of background lighting, the subject can tend to appear as being in front of nothingness and have little visual dimension of depth. The common use of background lights then is to illuminate the background to the degree desired and to separate the subject from the background, giving the sensation of depth.

The background light, as its name implies, is used to light the background separately from the subject. Using a seamless paper background, the photographer has an opportunity to use lighting to create a background that does not actually exist in the room. Instead of just lighting the paper, many photographers will “paint” a scene with background lights. The simplest way of doing this is to place one light between subject and background or to one side of the subject, with the light aimed at the background. By altering the position, elevation, angle, and degree of diffusion, a strong or slight gradient of light to dark may be impressed on the background, forming a frame or halo which enhances the subject.

Careful visual observation of the overall effect can lead one to proper positioning and structure of the background lighting. For instance, if some part of the subject is dark, or weakly lit by the front lights, this can be a good area to have substantial illumination of the background. By contrast, lower light levels on the corresponding portion of the background can bring out light colored or brightly lit portions of the subject. Many other interesting effects can be obtained with background lighting. Colored filters or gels may be used to project background hues. Multiple lights and filters can produce very interesting backgrounds.

Back Light and Hair Light
The second type of rear lighting commonly used is the back light. This light will be used at some position behind the subject, but will be pointed toward the subject to light it from behind. Back lighting can work wonders to emphasize the subject and to visually separate it from the background, particularly on hair and clothing.

When back lighting is specifically directed to the hair, it is called hair lighting, and can offer a spectacular effect. For example, a dark haired model against a dark or even neutral background can appear dull and ill defined with only front lighting. Once the hair is backlit, the individual strands sparkle with light. The definition is enhanced, as is the sensation of depth and separation.

Back lighting can also be very effective as an apparent main source of light – an example being the sort of silhouette effect that occurs when sunlight falls over a person’s shoulder. In the studio, interesting shots can be made by placing a back light at a sharp angle behind the subject and adjusting frontal light to achieve not a silhouette, but the hint of one. Back light can also be used to add a rim of light around part of the subject.

Dramatic effects can also be obtained by using rather pronounced coloration on back lights, such as an intense blue filtered light streaming through black hair. “Party” colors from behind can introduce a feeling of nightlife. Yellows and ambers can hint of sundown. It’s often useful to employ partial light blocking shields (or gobos) on back lights to prevent spill or unwanted light onto the foreground or into the camera lens where it can cause flare or ”fogging.” Snoots, barndoors, gobos or other light shaping obstructions can be used.