In the first of a series about lighting equipment it seems worthwhile to begin by considering if artificial light sources are still necessary at all. Randall Miles, Lighting Consultant and former Product Manager of ARRI GB, asks that you...

"Don't Forget the Lights!"

One could be excused for believing that because of the ever increasing sensitivity of video cameras, the need for artificial lighting would diminish, even disappear! This is most certainly not true, particularly if good quality pictures are required.

Certainly, the modern day video camera, if pushed to the extremes of its sensitivity range when the illumination level is abysmally low, can produce pictures of surprising clarity. However, these pictures tend to be extremely contrasty and very grainy - to use a photographic analogy. Lighting is required in an overall sense, to improve the clarity, decrease the noise (graininess) and also to reduce the contrast. Providing a certain minimum level of illumination is the first technical requirement, but not the only one.

The human eye and brain are far better than any media in being able to observe highlight and shadow detail. There is a considerable amount of interpretation by the brain of what the eyes are seeing. In other words, we observe largely subjectively. No camera can do this. It is totally objective.

This technical limitation is a question of the contrast range or more correctly, the acceptable contrast range that can be reproduced not only by the film or television camera but also - and this is important - by the display method - the projection or TV screen. The majority of "natural" scenes - although quite acceptable to our eyes - would be displayed through either medium as too contrasty.

As exposure in both film and television is largely determined by the bright areas, such a scene would probably have important details concealed in large heavy black shadows. It is this contrast - or the control of it - that is a second technical requirement that lighting fulfils.

Imagine taking a shot of a person in a room, seated in front of an open window in daylight. Let us, for example, say the level of brightness from the window is 5000 units, the face where illuminated has 100 units and the face in shadow has 1 unit. In this case, the facial contrast range was 100 to 1. Overall range was 5000 to 1. Both exceed that which could be reproduced by either film or TV, although there would be no problem viewing this scene directly with your eyes.

By having a light on, or near to, the camera, which produces its own illumination of say, 100 brightness units overall, then the contrast ratio is severely reduced. In this example, the highlights would have an illumination of 100 + 100, and the shadows of 1 + 100. Now instead of a contrast ratio of 100-1, the extremes of light and shade, after the supplementary lighting has been switched on, is now reduced to about 2-1 (in fact 200 to 101). The brightly lit window, relative to the lit side of the face would be 5000 to 200, that is, 25 to 1 and to the shadow side 50:1. All of this would just be clearly reproduced by either medium.

In all of this, because a camera is objective, it will reproduce any inaccuracies of colour exactly, which when viewed on a TV screen will show up as obviously wrong. If these inaccuracies are looked at in the original scene the mis-match will be less obvious (except to the trained eye) due to the brain's interpretation. Therefore it is important to take into consideration and measure if necessary, the colour temperature of the illuminants used and correct if required. For example, incandescent sources may require filtering which result in the loss of 75% or more of the light from the lamphead. The characteristics of the various technologies available will be considered in more depth in future articles.

All this of course, is disregarding the use of colour for effect which is an entire subject in itself.

One further, but often forgotten need for a certain level of lighting is the effect it has on performers - particularly for more theatrical scenes - where they require a sense of being lit, of brightness, the feeling of being in the spotlight. Reverse this sense of occasion and it will have a depressing effect on performers.

Apart from the technical requirements of lighting, the most important part it plays in the final reproduced production can be broadly called artistic. It contributes to a production often without being noticed except when spectacular lighting is used to glamorise and enhance a lavish, often musical sequence for example. In such cases it becomes a part of scenic design.

This is a brief list of some of the Artistic Requirements of Lighting:

• Lighting can help to create an illusion of depth, solidity and perspective on a two dimensional screen. To make the images believable.
• Lighting can help the composition of the picture by the relative positions of tones and colours, and to direct the viewer's attention to the important parts in a scene
• Lighting helps to fulfil the explicit script requirements of the time and place of action (Day, Night, interior, exterior and the many variants). These are often suggested by the apparent source of light inside or outside the scene.

  Examples are: sunlight out of doors, or through windows; Moonlight or streetlights at night; Room lights inside at night - or even (apparently) complete darkness!

• Lighting should interpret and establish the requirements of the script, mood, feeling, atmosphere and - particularly in musical type productions - the tempo or pace.

The final pictures and the lighting must be "right" for that production, for that scene.

The lighting must contribute to a production. When well done it is often not noticed - and only noticed when it is wrong!

It has been said that the artistic Lighting man, Director of Photography, Lighting Cameraman, Lighting Director, actually "PAINTS" the scene with light. An artistic painter needs to know his materials, his media and instruments of use, his canvas, his brushes, his paint, pencils, etc. In much the same way, a lighting man needs to know his instruments, the various kinds of lights and accessories that he can use to achieve the results that he wants. When not to use some of them and sometimes when to adapt others to meet his needs. In the next article, we will look at the some of this range of available instruments and their various strengths and weaknesses.

Written by Randall Miles, edited by Andy Barnett, Technical Support Engineer for Arri GB.

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