Theatre Lighting

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Theatre Lighting
By Adam Lipszyc
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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 audiences attention and
  focus where you want it.

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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.

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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.

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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.

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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 thats 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.

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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.

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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, youd make the
  precious scene dark. If you want a pool of light
  to seem very cold youd 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.

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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 actors face to
  highlight its shape and movement.
• Similarly, if one actor is to be spotted out or
  emphasised, its very normal for the light to be
  distributed so that more light strikes the more
  important actor.

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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.

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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.

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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.

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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.

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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 its designer, Augustin Fresnel.

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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.

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Lanterns/Spotlights

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

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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.

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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.

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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.

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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.

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Colour Mixing

• The theory is that all colours are made up of
  only three pure or primary colours. Whilst in
  theory its somewhat inaccurate, in practice its
  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.

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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.

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Subtractive Colour Mixing

• So far weve 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.

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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.

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The End