Photography is essentially about capturing light. Most of the light we capture in photography is reflected light from objects. There are exceptions such as the blazing light from a fire or light from a burst of fireworks or lightning. Light can be of a difuse nature, not emanating from a fixed source and this type of lighting can produce a very subdued and pleasing effect. Light can also be from a point source be very harsh and produce very hard shadows. Light can also come from different sources to produce different color effects. In every day life we see daylight, moonlight, artificial light, tungsten, fluorescent, infrared, flood lights, mercury vapour lights. In photography light creates the image. Light travels in straight lines and the further it gets from the source the weaker it gets.