Friday, 10 October 2014

THEATRE STAGE LIGHTING



Lighting can be very important for many types of event. It can provide illumination to see by, can suggest moods, can emphasize shape and texture and can direct the audience's attention to the area you want. Once the purpose of the light has been decided the correct equipment to create it must be selected and carefully positioned and controlled. This short tutorial is aimed at explaining the basics about lighting - the tools at your disposal and some of the fundamental design principles. We hope it will give you the necessary information to get you started but we are always on hand to help and advise if you get into difficulty.

Choosing Lighting Fixtures
There are a variety of different lighting Fixtures (aka Lanterns, Lights) at the disposal of a lighting designer. These can be split into 4 basic categories : Wash Lights, Spot Lights, Beam Lights and Flood Lights. These can also have other names but we'll work with these for the present.

Lighting can be very important for many types of event. It can provide illumination to see by, can suggest moods, can emphasize shape and texture and can direct the audience's attention to the area you want. Once the purpose of the light has been decided the correct equipment to create it must be selected and carefully positioned and controlled. This short tutorial is aimed at explaining the basics about lighting - the tools at your disposal and some of the fundamental design principles. We hope it will give you the necessary information to get you started but we are always on hand to help and advise if you get into difficulty.
Choosing Lighting Fixtures
There are a variety of different lighting Fixtures (aka Lanterns, Lights) at the disposal of a lighting designer. These can be split into 4 basic categories : Wash Lights, Spot Lights, Beam Lights and Flood Lights. These can also have other names but we'll work with these for the present.

Wash Light
Produces a soft edged beam which looks quite natural. Beam size can normally be adjusted and multiple sources blend together easily. There are a few sub-categories of these; fresnels, prism-convex and pebble-convex. The Fresnel is probably the most widely used of these.
Spot Light


Spot Light also known as a Profile Spot, this has a more complex lens assembly and allows you to focus the beam so that you can have a soft edged beam like the wash light or a hard edged one. Most Profile spots allow you to insert a Gobo - a metal disc with cut-outs - to breakup the light or to project shapes and images. This can produce a variety of effects.


Beam Light
The Beam Light is a little different as all the optics (reflector, lens, etc) are contained in the lamp (aka bulb). This brings the cost of the fixture down but the lamps are a little more expensive. The most common example of this fixture is the Parcan. These lamps produce a very intense beam of light which can be very effective although there is no control over the beam and the spread is a little uneven. Used extensively in Rock'n'Roll due to the intensity of the light which works well with strong colours.



Flood Light


Last, but not least, the flood light. This has no adjustable controls and produces a very wide spread of light. It is normally only used to illuminate backdrops.The choice of lantern will then depend on the application. Wash lights produce a more natural light and are therefore suited more to theatre and film. Live music favours a more intense and visual form of lighting and therefore beam lights are the normal choice along with spotlights for effect.

Power Requirements
An important factor to bear in mind is the amount of electrical power required to use these lanterns. They are rated much higher than normal domestic lamps with power ratings between 500 - 2000 Watts. It is important that you do not try to overload the mains supply at the venue. The following table gives the approximate current requirements for the most common lamps. All ratings assume a 240 volt mains supply.

Lamp Power Rating
Current Required
500 Watts
2.1 Amps
650 Watts
2.7 Amps
1000 Watts
4.2 Amps
1200 Watts
5 Amps
2000 Watts
8.3 Amps

Bearing in mind that you may be planning to run the lighting rig off a 13amp socket, it is easy to see that you will not get many lanterns running without blowing the fuse. One way around this is to use more than one wall socket. The typical ring main in most buildings is rated at 32 amps. However. other services in the building may already be using some of this so you will need to do some checking to see if the available power is sufficient.
Dimming and Control
If you just want to provide basic light then the lighting can be plugged straight into the mains To allow control and creativity you will need to employ some kind of dimming or switching.
Dimmers allow the voltage being fed to the lamp to be varied and hence the output of the lantern can change to. Dimmers come in various shapes, sizes and configurations. The most common form for touring use is the 6 Channel Dimmer Rack. This provides six independently controlled channels. 
Control of lighting requires a control desk which sends electrical signals to the dimmers to set their levels. These may range from a simple 6 slider panel to an 'all-singing, all-dancing' state-of-the-art computer control system. Generally, if the lighting requires only basic dimming and the changes are not too complex then a manually controlled board with faders will be fine. If you require lights to 'chase' in sequence or the 'cues' are very complex and numerous then you will be looking for a control desk with memory and effects Rigging capabilities.
So, you've decided on what lights to use and how you will power and control them. The next step is where to put them.
There are several options when it comes to 'hanging' or 'rigging' lanterns.
They can be hung from bars. . A 'Hook Clamp' is used to attach the lamp firmly to the bar.
Trussing is commonly used now to hang lamps. It is comprised of aluminium alloy tubing arranged in a triangular or square box section. It is considerably stronger than a single bar and is manufactured in many different permutations to allow for many types of rig.
 Stands can support a single lamp or several lamps using a T-bar, a horizontal bar which attaches to the top of the stand. .
Finally, lamps can be set of the floor or on other objects. Some lamps can get very hot, however, so some form of low stand is commonly in order. Again, you should take care to avoid placing such lamps where they may be a hazard to people.
Focusing
Its no good simply hanging a few lanterns and turning them on - the result would look patchy and would more than likely fail to light some of the desired areas. Each lantern needs to be 'Focused' to point to the correct place with the desired beam angle and focus. However, when done correctly, the lighting should be seamless and look fantastic.
he most natural positioning is to have the lantern above and in front of the subject at about a 45° angle. 
In practice, a single lantern cannot provide a natural light. Multiple lanterns are used to achieve this. For example, two lanterns above the subject at a 45° angle - one to the left and one to the right both pointing in towards the subject.

Plotting
Now that you have hung and focused your rig, you need to use all the fixtures to light your show. This part of the process is known as the Plot.
during the 'Plot' various lighting states are created to light the performance area. These lighting states are referred to as Scenes or Cues. Some shows may require just one lighting state (or Cue) whereas others - like some West End shows - use hundreds. During this process, the Lighting Designer (LD), the Lighting Operator and the Director will sit down and go through the show building each lighting state and recording it as a Cue for recall during the show run.


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