Lighting Basics

Lighting – without it the camera cannot create an image. Yet with it comes a host of questions and potential problems – Where do you place the lights? How many of them? What type? What filters and coloured gels do you use? In this article we’ll take an introductory look at the basics of lighting, by defining a few terms and examining a few key concepts. When you’ve finished this article, you might want to check out my other one on three point lighting.


Talking About Light

When talking about light, it’s important that we define a few terms before we begin. In common day conversations we may use terms like “soft light” and “low light” almost interchangeably, but a more precise use of the language is required here if we are to avoid confusion. For the purposes of film making, light can generally be described by using the following variables: Brightness; Direction; Colour; and Quality.

Brightness

Brightness (sometimes referred to as the “quantity” of light) is not too difficult a concept in itself, but the way cinematographers talk about a light’s brightness is confusing to newcomers. During a shoot cinematographers do not usually refer to the lamp’s actual objective brightness (measured in foot candles or lumens etc), but usually refer to how many “stops” over or under the light is compared to other lights or to the ideal exposure.

I’ve discussed stops and how they work in another article, but for the purposes of this introduction stops mean just this – each stop is a doubling or halving of the light’s brightness. If a light is twice as bright as another one it is one stop brighter, if it is four times as bright it is two stops brighter, if it is half as bright it is one stop under, etc.

Direction

Another fairly easy concept is the light’s direction, or where it’s coming from. This includes not only the lights angle on the subject, but also its relative height, and is sometimes referred to as the light’s “throw” or “distribution”. For simplicity, we’ll include the light’s cone angle or spread within this term.

Colour

When we refer to a light’s colour, we are not necessarily referring to brightly coloured filters used for effect. More often than not, we are usually referring to is the small differences in colour between various types of light sources. For example, the apparently “white” light from a light bulb with a standard tungsten filament is actually a different colour to the apparently “white” light from daylight. Tungsten bulbs give a more orange light than daylight, or to put it another way, daylight gives a relatively blueish light compared to bulbs. We don’t normally notice this difference as we go inside and outside as our brain automatically compensates and corrects the image it sees.

However, to ensure that our picture has the correct colour balance we need to use the right film (daylight film for outdoors or tungsten film for bulb-lit interiors) or, in the case of video, make sure the camera’s “white balance” is set to the appropriate colour. We’ll go into the issue of colour correction and white balance in more detail in a future article.

Quality

This is one of the harder concepts to define for the newcomer to lighting. The quality of a light is usually described with the terms “hard” and “soft”. These terms do not refer to the light’s brightness, but to the quality of the light it gives, and to the hard or soft shadows it produces. A relatively small light source (that is, small in size, not in brightness) will give hard-edged shadows that are typically dark (assuming no other light sources). A large light source (where the light-producing element is large in size) will give soft- or fuzzy-edged shadows that less dark.

For example, on a bright clear day, our shadow is hard-edged and fairly dark (the sun is so far away that it’s effectively a small source of light), whereas on an overcast day the sun lights the clouds, and the clouds become a very large light source, which casts a very soft-edged grey shadow. One way of thinking about the difference is to imagine that a soft light source is really a collection of millions of tiny hard sources, whose shadows all overlap slightly giving a fuzzy edge to the shadow.

A lamp with a small exposed bulb which casts light directly onto the subject will typically give a hard light, whereas a lamp which first bounces its light off a screen or pushes it through a diffusing filter before it reaches the subject will give a softer light. In the latter case, the screen or filter is effectively the light source.

Controlling Your Variables

When reading the following definitions, remember that each variable can be regarded as independent from the others. For example, a hard light source could be bright or dim, orange or blue. A blue light source could be directed from up high or down low.

However, you will discover that certain types of lighting are typically used in certain ways, so that there is a certain informal relationship between some of these variables. In another article, we’ll look at the simplest implementation of these lighting types – three point lighting. Once understood, three point lighting will give you a head start in lighting anything, from an interview to a dramatic scene.


Look Around You

Until then, take a look at the lighting all around you. Is it hard or soft? Blue or orange? What angle are the shadows? Appreciating the lighting in everyday life will help you mimic it (or distort it) when you come to lighting a scene.

Updated: 8 July 2000
Originally written for About.com’s Filmmaking page.