1 Introduction to Lighting
What we sense as ‘light’ is a range of wavelengths within the electromagnetic spectrum which can be perceived by us through our eyes (visible light). At the low end of this range we can perceive infrared and reds, and at the high end blues and ultraviolet.
The three basic properties of light are: Frequency (or wavelength), which is perceived by us as the colour of light; Intensity (or amplitude), which is perceived by us as the brightness of light; and Polarisation (or vibration angle), which is a barely discernible property to humans but does have an effect on some aspects of video production.
Light rays through camera lens
The human visual system is incredibly adaptive and we take light very much for granted. We see by it every day and it is probably the most changing element in our daily life. Take a careful look at the buildings and other objects around you – do they appear to change during the course of the day as the time, weather or the source of light changes? Yes of course they do.
The example below shows how the appearance of the buildings and the statue changes during the course of the day. Lighting for video is important for a number of reasons.
These include providing sufficient illumination to enable the camera to generate pictures; to model and shape a subject; and to create mood or atmosphere. Natural and ambient light can be manipulated to make better use of it; and there are also various types of artificial light available – including tungsten, fluorescent and LED (Light Emitting Diode) – with various means of positioning and applying them. Whilst a single camera mounted light will provide the videographer with sufficient light for recording pictures of close subjects, it will not be adequate for subjects at distance from the camera. A single lamp will also not provide any means of modelling the subject.
Creative lighting is not necessarily about just adding additional light sources – it’s also about modelling and creating shadows. Video is watched on a two- dimensional medium (a screen), so we must use light and shadow as a method of trying to re-create the three dimensions we see with our binocular vision.
Quite often additional lights are only used to compliment or balance natural or ambient light – such as that falling on the subject from a window or from normal room lighting. Truly creative lighting is regularly about taking light away rather than adding more!