The Objective of Good Lighting

Introduction-To-Television-Lighting

Lighting is one of the aspects of Television production usually taken for granted when used correctly. However, poor use of lighting can lead to glaring problems and inconsistencies, as the camera requires a certain amount of lighting to create good tonal range. This is especially true of television cameras, which require a wider lens aperture in low-light environments (thus reducing the depth of field); conversely in high light environments, there is a risk of images becoming overexposed.

Although sometimes the only solution is to change the camera angle, artificial lighting can be used to make the lighting environment more suitable.

 

The purpose of good lighting, however, is not just about good visibility – it has artistic applications as well. A director can use lighting to convey mood, time of day, location and overall scene atmosphere.

Good lighting use is also important when it comes to creating depth by highlighting and accenting certain things (much as in painting); consistent lighting allows the subject to appear more three dimensional.

Measuring and Using Light

When considering light as a tool in television production, there are four basic aspects one should consider: intensity, color temperature, dispersion and direction. Let’s start with intensity:

Intensity

Intensity is basically the level of light required to illuminate a filming location or set. Given that different camera specifications require a certain light level for a given f-stop. Many cameras come with a built-in “zebra exposure indicator,” which assists by allowing camera operators that ability to evaluate over-exposed regions of a shot by highlighting them. The most effective way to evaluate lighting, however, is to view the shot on an actual monitor where a technician can assess both the artistic and technical qualities of the shot.

There are two basic ways by which lighting can be measured: incident and reflected. Incident light measurement is used to gauge light levels from different directions. When measuring incident lighting, the light meter should be positioned near the filming subject and pointed at the different converging light sources to measure the amount of light that the subject is receiving.

Reflected light measurement gives an indication of how much reflected light is actually reaching the camera. Using reflected light allows a technician to get a reading on the total amount of light reflected by the entire scene.

Color

Although the human eye is adapted to see and categorize many different spectral configurations of light as “white light,” there is usually a varying mixture of colors from the spectrum. Differences in the amount of red, orange, yellow, green, blue indigo and violet are contained in the light at different proportions.

Color “warmth” can be corrected in one of two ways: either by adjusting the camera’s color-correction filters or by adjusting the color temperature of the light to better fit with the camera’s color balance. The camera’s white color balance can be adjusted by pointing the camera at a white surface and then altering the white balance using the camera’s built-in “white balance” feature.

Color temperature can also be adjusted by using in camera filters (on camera for the “old school”). For example, a blue filter material can be incorporated in tungsten lights to raise the color temperature. It is important to note that although cameras are usually configured for the dominant light source; different light sources have different qualities.

Dispersion

Using different types of lighting allows alterations in the dispersion of light. Using different light sources can allow a technician to produce hard and soft light (less and more shadow emphasis).

Spotlights are a concentrated light source for example, can be used to produce hard light. Spotlights produce sharp shadows, create well defined modeling and can be used to localize light in certain areas. Spotlights are also used to project light over large distances.  Note that the sun can also be used as a spotlight under the right conditions.

Floodlights, on the other hand, are used to produce soft light, which is scattered and diffused. The Soft-light generated by a flood light is characterized by being shadow-less, scattered and diffused. This effect is similar to the conditions one would see during a cloudy overcast day.

Direction

Lighting direction refers to the positioning and direction of available lighting. The direction of light determines the way in which light and shade interact, and thus can be used to highlight what features to focus on, and what can be allowed to fall into the shadows. Direction can be altered by changing the angle of, raising or lowering, or repositioning the lamp.

Lighting Methods

Three-point lighting (known also as triangle or photographic lighting) is a basic method of using directional and diffused lighting to generate the best results.  A key light (usually a spotlight) is positioned directly above the camera.

A fill light is used on either side of the camera (right or left), to reduce the shadowing created by the spotlight, and a back-light is placed behind the camera. The back light is placed at a higher point and angled onto the filming subject – this is used to emphasize the subject’s shape.

Normally, the key and back-lights are of the same intensity; however, sometimes a reduction in back-lighting may be necessary for lighter hair color. The fill light is usually kept at a fourth or a third of the intensity of the other lights.

People

When it comes to generating good lighting for filming a single subject, it is generally accepted that the key light should be placed on a wide angle with the fill light. There should be no more than one key light for each view-point, and shadows should be reduced by an appropriately placed soft light. Steep lighting is not recommended.

Groups of People

Filming groups of people can get a bit more complicated. Although sometimes a single light may be adequate, variations in positioning, clothing, skin and hair color can confound matters.  In this case, a lighting technician can use diffusers to correct the situation. It is also possible to light up subsections of a group (as is the case when filming orchestras and bands).

Areas of a Scene

When lighting up a scene, it can be infeasible to alter the lighting setting for each different scene. Sometimes it may be advisable to use a systematic series of three point lighting configurations.

Tools for Controlling Lights

Lights can be manipulated by using different tools and techniques. Dimmer boards are electronic systems that can be used to adjust the brightness of the lights remotely from an electronic panel.

Barn doors are adjustable flaps can be used to manually restrict lighting in situations where certain walls need to be shaded, or if there is too much light shining into the camera.

Flags (curtains mounted on a stand that can be used to block out a light source) and diffusers can be used when and where needed to suppress light.

Light filters and cookies are attachments that can be added to certain types of lights control the color and pattern.

Putting it Together

Before beginning a production, it is necessary to have information on the set. Things like the subject, the type and position of the cameras and the general layout of the studio/shooting area are needed to produce a strong lighting plan. Based on this information, a lighting technician can create a lighting plot (usually based on the three point lighting system).

Come camera rehearsal time, a good lighting technician should pay attention to the monitors to check for lighting defects.  These defects can include issues with audio boom shadows, poor contrast, areas that are too dark or too bright and other kids of interference. These issues should be noted and corrected during breaks.