Theatre Lighting

Theatre Lighting By Adam Lipszyc

Objectives of Stage Lighting • There are four objectives of stage lighting. • Selective Visibility • Making the performer visible is the most obvious function of stage lighting. The lights position, intensity and colour all require very careful consideration. Just as it is possible/necessary to make an actor/performer visible, it is possible to make others appear less visible, and emphasise just one person. • This ability to use selective visibility is very useful for getting the audience’s attention and focus where you want it.

Objectives of Stage Lighting 2. Indication Setting • The audience is usually familiar with many different environments. For example, if we are outdoors we expect certain light conditions. If we are in a lightning storm; dark with flashes of white light.A warmly light fireplace; a dim warm glow. • These lighting conditions are recreated on stage, making for a believable and more importantly, an understandable situation. • Of course, light is not the sole factor of a well-done recreation of an environment, you also need sound and scenery.

Objectives of Stage Lighting 3. Creation of Mood • For whatever reason, we normally connect certain lighting states with certain moods. The happy party atmosphere goes hand in hand with bright, colourful light; the soft glow from the fireplace is often associated with romance; and so on. • If the stage has ‘happy lighting’ it should be easier for the actors to play a happy scene.

Objectives of Stage Lighting 4. Elements of Composition • The audience is presented with two things; what they see and what they hear. What they see and hear must keep their attention and must convey some sort of message. This message could be an idea, a moral or just simply entertainment. In any event the visual message must be interesting to look at. • Visual composition relies on colour, lights and shade, and movement. • A stage, evenly lit, with all the actors standing in a line is very boring. • The distribution of light-its colour, its shadows, its changes- can contribute to a more interesting and more compelling visual image.

Compromise • Unfortunately, the objectives often cut across each other. • Lighting that is good for a certain mood may be terrible for visibility. • The lighting that most strongly establishes a setting may destroy an interesting visual composition. • There is always a need for compromise, little adjustments here and there, until the best balance of objectives is achieved. • ‘Style’ is a word much used in theatre and essentially that’s what we have just discussed. The particular balance of the objectives that has been worked out for a particular production is the lighting style for that show.

Usable Properties of Light • There are four Useable properties of Light • Intensity • The quantity of light is called intensity. • Built into our eyes is a device which allows the eyes to adapt to levels of light intensity during the day and night (iris). • ‘Intensity is Relative’, meaning; light is bright in relation to the room, but if the same light was to be taken outside it may seem quite dull. • In general, the more detail, the more light required.

Usable Properties of Light 2. Colour • Colour must be carefully controlled. This is usually done with colour filters. As with intensity, colour is, to a degree, relative. A so-called ‘cool light’ may only appear if there is a warm colour to compare it with. If you want a scene to be particularly bright, you’d make the precious scene dark. If you want a pool of light to seem very cold you’d contrast it with a warm surrounding, or use it after a warmly-lit scene. • The proper use of contrast is important for clarity and effectiveness on stage.

Usable Properties of Light 3. Distribution • As I mentioned earlier, ‘seeing’ an actor on stage needs more than a simple light hung over the stage. In order for the audience in the back row to see facial expressions, special lighting conditions are necessary: the light needs to create a certain contrast on the actor’s face to highlight its shape and movement. • Similarly, if one actor is to be spotted out or emphasised, it’s very normal for the light to be distributed so that more light strikes the more important actor.

Usable Properties of Light 4. Movement • The last Property Light. Intensity, colour and distribution, aren't ‘static’ colours. All three of them are subject to change and these changes are called ‘movement’. • Too many changes in lighting may be distracting to an audience, yet too few may contribute to boredom.

Inverse Square Law • When a beam of light leaves a spotlight, the area illuminated by the beam increases as it goes farther from the spotlight. The same quantity of light must illuminate larger areas. It can be shown mathematically that if the distance from the light source to the surface is doubled, the intensity drops to one-quarter of the original. This happens because the illuminated surface is now four times bigger. • Also, ‘the distance from the light source to the surface’ is know as the ‘throw’. • The farther light source is from the surface, the longer the throw.

Reflection • Whenever light hits a surface, a proportion of it will be bounced off again and the remainder will be absorbed due to the pigments in the surface. • This bouncing off is called ‘reflection’. • The lighter the colour of the surface: the more light will be reflected, and the greater the sheen: the greater the degree of reflection. • Some surfaces, such as polished metals, are very efficient reflectors and can be used to control light. • These type of reflectors are often found in theatre lights and are used to improve their efficiency.

Lenses • There are two families of lenses found quite often in theatre lighting. • Plano-Convex Lens • This lens has a smooth surface and is used when the beam of light must have a well defined edge. • It is recognized by its smooth surface and outward curve. Lanterns using this lens have a hard edge to their beam. • The size and thickness of lenses vary according to the job they must do.

Lenses 2. Fresnel Lens • This lens is recognized by the circular moulding on the front. Lanterns using this lens are efficient and have a soft edged beam. The lens is named after it’s designer, Augustin Fresnel.

Lanterns • To clarify; the term ‘lantern’ is used to describe the specialised lighting fittings used in theatre work. • The two most often used are floods (floodlights) and spots (spotlights). The essential difference is that floods give a wide spreading wash whereas the spot gives a beam of light or a directional light.

Lanterns/Spotlights • Lanterns with lenses are almost always spotlights.There are two main types of spotlights. • Fresnel • Profile

Lanterns/Spotlights • Fresnel • These spotlights obviously have Fresnel lenses. • When we say that the beam of the light from a Fresnel has ‘soft’ edges, it means that the centre of the beam of light is bright and gradually darkens towards the edge. • The soft edge of the Fresnel lanterns make them easy to use. The lantern beams readily overlap and the result is smooth coverage of light.

Lanterns/Spotlights 2. Profile • Most profile spots (spotlights) use Plano-convex Lenses and as a result, the beams have clearly defined edges. • As well as clearly defined edges, the beam of light is also even in intensity from edge to edge, making it appear clean and evenly distributed. • Not only can the beam be circular but by using shutters you can introduce square beams, semi-circular beams and even triangle beams.

Colour Filter • White light is a mixture of coloured light. All the colours of the spectrum are present and the way we get coloured light on stage is to filter out the unwanted colours. • If I wanted to get blue light, a filter is used, and this colour filter will only allow blue light to pass through it. All the other colours are absorbed by the filter. This absorbed light becomes heat and causes the filter material to fade and to become quite soft.

Colour Reflection • When light hits a coloured surface the effect is similar to the colour filter; if white light hits a red surface then red light its reflected. • Also, if pure red light hits a pure blue surface, no light will be reflected because the surface can reflect only blue light.

Colour Mixing • The theory is that all colours are made up of only three ‘pure’ or ‘primary colours’. Whilst in theory it’s somewhat inaccurate, in practice it’s basically true. The process is simple; if the three primaries-red, blue and green-are mixed in the correct proportions, white is the result. Red and blue mixed make magenta, and so on. • This is not an efficient way to get the various colours as it uses too many lanterns and wastes too much light.

Colour Modification • The theory of primary colour mixing is additive colour mixing –light plus more light. In its basic form the theory isn't much use but it may be used as a basis for considering the effect of coloured light on various surface colours. • If you shined white light onto the stage with an amber surface, it will reflect both green and red (because they make amber). This causes problems because an amber dress may not look amber in contrast to the reflecting colours. • Tints; are simply weak colours. A pale pink is white light that has been filtered so that red dominates over blue and green, which are still present.

Subtractive Colour Mixing • So far we’ve discussed additive colour mixing-light plus light. It is also possible to mix the actual filters. • What happens if two filters are used instead of one? Take an amber filter and put a magenta filter with it.Amber light is red and green, so red and green light pass through the amber filter.On the other hand, the magenta filter allows only red and blue light through.The result is red light. • I might seem stupid, we could have just used a primary red filter in the first place. However when dealing with tints, it is possible to combine filters to make colours not otherwise available.

Dimmers • The amount of light generated is dependent on the temperature of the filament. The filament is heated by electrical energy passing through it. Control the flow of electrical energy means control over the temperature of the filament and therefore; control over the amount of light. • A dimmer is simply a device which regulates the flow of electrical energy through a lamp/lamps.

The End

Theatre Lighting