Qualities of Light Sources

Qualities of Light Sources

In practical terms, light sources can be discussed in terms of the quality of the light they produce. These qualities are critical to the result and must be understood when choosing the source for a lighting plan.

How light is generated

Most natural light comes from the sun, including moonlight. Its origin makes it completely clean, and it consumes no natural resources. But man-made sources generally require consumption of resources, such as fossil fuels, to convert stored energy into light energy. Electric lighting is superior to flame sources because the combustion of wood, gas and oil produces pollution within the space being illuminated. Moreover, electricity can be generated from natural, nondepletable sources of energy. Including the energy generated by wind, hydro, geothermal and solar sources.

The Spectrum of Light

The spectrum of light is seen in a rainbow or from a prism, and it includes all of the visible colors. We tend to organized color into three primaries (red, green, and blue) and three secondary’s (yellow, cyan and magenta). When primaries of light are combined, the human eye sees white light. Historically, using a filter to remove colors from white light generated colored light. Blue light, for instance, is white light with green, and red removed. Filtered light is still common in theatrical and architectural lighting. However most nonincandescent light sources tend to create specific colors of light.