An understanding of basic film lighting techniques can elevate any filming project. Once a filmmaker has a grasp of basic lighting techniques, he/she can begin to experiment with the lighting to create whatever effect he/she desires. Lighting can be provided with artificial lighting kits or by natural lighting systems, such as daylight. Everything you see on film looks the way that it does because of the lighting. Without proper lighting, films look amateurish. The subjects shown on film are difficult to see if the lighting is poor. Effective lighting not only illuminates the subjects, but also adds mood, ambiance and helps the filmmaker to tell the story. One basic, critical principle at the heart of most film lighting is the notion of three-point lighting. As you read through this, check out the sections explaining three-point lighting: Key Light, Fill Light and Back Light.
Why is Lighting Important?
Lighting is used to illuminate the actors, sets and props within a given scene. Without proper illumination, the audience will literally be left in the dark. In addition, lighting techniques can define the genre and atmosphere of the project. For example, documentaries depend on natural light when interviews are taking place outside. Scripted films may require a sharper look and may require artificial lighting techniques.
One important aspect of lighting is correct exposure . This is controlled through a number of contributing factors, including lens choice, lens aperture, camera filteration, electronic signal amplification and lighting. When lighting a shot, enough light has to be presented in the scene to allow the camera to perform at its optimum and this means understanding the limitations or ‘dynamic range’ of a given format or camera. For example, standard definition video cameras have about 5 f-stops of dynamic range. That is, there are 5 exposure points of difference between the ability to resolve detail in both the shadow (dark) area of the scene and the highlight (bright) areas of the scene simultaneously. HD cameras can have as much as 8-12 f-stops of dynamic range. The human eye can resolve much more than that. It’s difficult to measure exactly how much because our eyes adjust so quickly to contrast in a scene, but it’s estimated that we can see about 15 f-stops of range in a given scene. The actual number is less relevant than understanding that cameras are much more limited than our eye, and so you have to use lighting to capture the important parts of the scene so that they fall into the ‘resolving’ capability of the recorded image.
Another important aspect of lighting is creating the mood. Light color, light intensity and light quality all contribute to creating mood in a scene. To light to best effect, you should always motivate where light comes from and use realistic colors that are natural or appear to emulate our environment. Light comes in 2 core colors, orange light and blue light and all shades in between. Daylight is fundamentally a cool light with tones that lean towards blue. Artificial light such as a candle or a household tungsten bulb are much more orange in color and are often referred to as warm lights. Light is measured scientifically in ‘Kelvin’ using the visible light portion of the electromagnetic spectrum. So, the cooler the light in color, the higher the number in Kelvin, daylight therefore is measured as 5600K. The warmer the light in color, the lower the number in Kelvin. So a household tungsten bulb, for example, is measured as 3200K. You will come across this a great deal when shooting video as the camera also has the ability to set a color balance and this is measured in Kelvin. So, a daylight camera color balance is 5600K and a tungsten camera color balance is 3200K.
The Key Light is the most important light in any shot. The job of the Key Light is to take the place of normal natural light sources. This might be light in outdoor shots, or light that comes in a window. Savvy shooters obtain Key Light from the sun when shooting outdoors and replicate it artificially when shooting inside. If viewers looking at a shot can tell where the light is coming from, this should be the Key Light that they detect.
Reflecting light is an important tool in the film lighting process – this is the Fill Light. The Fill Light is the light that makes a shot easier to look at. When a subject is only lit by the Key Light, certain areas are not going to be lit and some dark shadows are cast – this is an effect of light coming from one direction. The Fill Light appears from the side to fill in those dark areas and should be roughly on the side opposite to the Key Light. The Fill Light helps light up dark spots and shadows so they are not as sharp. Filmmakers can play with the amount of Fill Light based on how much shadow and definition is called for in the shot. To reduce shadows on the subject being filmed, the Fill light is typically placed lower than the Key Light. Filmmakers have the choice of using either an actual lamp or a reflector such as a bounce card as the Fill light. Either way, the Fill Light should reflect light back onto the subject in order to manipulate shadows.
Another important aspect of lighting is separating the actor from the background of a scene. Back Lights can be placed above and behind the actor being filmed to achieve this effect. The Back Light should never be aimed directly at the camera lens. A properly placed Back Light can outline — or create a subtle glow around — the actor. By creating contrast between shadow and highlight, the audience gets a sense of depth. Back Light is more important than many beginning filmmakers realize. While the Key and a Fill lights sufficiently illuminate the subject, it is the Back Light that gives the subject definition. A properly backlit subject should be clearly distinct from the background. This is not direct lighting, but rather subtle light from behind the subject that makes the border around the subject more distinct.
Once you understand WHAT it is you are trying to create, you can then look at the HOW to achieve it. That then moves you to consider what the most effective tools will be to ‘create’ your lighting setup – the subject for our next post.
Information for this post was taken from “Basics of Lighting” by Setla Film Productions and “Film Lighting Basics” on e-how.com.