This guide is a short introduction about lighting. It is geared towards production Managers and production coordinators to develop their understanding of lights they may be asked to order for particular jobs. Lighting cameraman may find some parts of the history of some lighting products interesting so please read on. This guide will also help with some of the jargon used in TV Production aufora.
In simple terms lighting is split into 3 main types, Tungsten, HMI & Fluorescent.
1) How does Tungsten work?
Well power is simply passed through a very fine wire coil, (called a tungsten filament) it heats up and glows ‘hot’ which in turn gives off light. The colour temperature of the light is around 3200k (similar to your bulbs at home)
2) HMI- what does it mean?
(Hydrargyrum Halide Iodide) lights have the same colour temperature as daylight (5600K to 6000K). They produce about four times as much light as a tungsten bulb with the same wattage. HMI lights work differently from Tungsten in that a spark ‘jumps’ or ‘Arcs’ between two pins and that spark ignites a gas which is held under pressure in the lamp housing. When that gas glow’s it does so very brightly. These lamps require what’s called a ballast. This is a heavy box that steps up the current and passes the high voltage to the lamp via a heavy duty ‘header cable’. (Remember never to look into an HMI when it’s on, it’d be like looking directly at the sun!)
3) Fluorescent- is that like strip lights?
In a nutshell yes these are based on the same principle as domestic strip lights. They are popular because they are light weight and give off a lovely soft light.
Standard Interview Light Kit
The kit we’re most often asked to provide consists of four tungsten lights: an Arri 650-watt or 800-watt light with a Chimera, an Arri 300-watt light and a Dedo light. We also include a gel kit with a range of gels and a reflector.
Here’s a brief description of each light:
Arri 800-watt light (Redhead)
It is an open-faced (there is no lens in front of the bulb) tungsten light. For interviews, this light is generally used with a Chimera (more on Chimeras in a minute) as a key light, the main light used to light a subject’s face.
Arri 650-watt light (mizar)
This is a Fresnel light – it has a lens with raised circular ridges on its outer surface which are used to focus the beam. It is often used instead of the Arri-800 and in such cases is generally provided with a Chimera. For interviews this is generally used with a Chimera as a key light. However you can also attach a gobo and this light can be used to throw a slash of colour on the background.
Arri 300-watt light (Mizar)
Like the 650-watt light, this is a Fresnel light. For interviews, it is commonly used as a fill light – a light to soften any shadows created by the key light, generally with some diffusion gel (more on gels in a minute) to reduce its intensity. These lights are also used as a backlight in an interview – a light directed from behind the subject to highlight the top of the head and shoulders.