Colour temperature is the foremost attribute of visible light and when delved into it can be a complex and intimidating topic to tackle. From a technical perspective; colour temperature is a numerical measurement, calculated by the response of black body radiators and the range of degrees of glow they go through during heating from cool black to white hot using the principle that any object, if heated to a high enough temperature will produce light in some form.
Colour temperature is measured in the unit of Kelvins and marked with the symbol K. Temperature can range from cool to warm on the Kelvin spectrum. Anything above five thousand Kelvins is considered cool light and anything below three thousand Kelvins is considered warm light.
To give you a clear representation of degrees Kelvin I will use standard benchmark for our perceptions of artificial light is of course natural daylight. Natural daylight read on the Kelvin spectrum measures somewhere in the region of four and a half to five thousand Kelvins.
Some of the specific Kelvin measurements are as follows:
• 2000k – 3000k is known as Warm White; found is standard 100w incandescent lamps, warm white fluorescents and warm white LED.
• 3000k – 4000k falls under the label of White light and can be found in tungsten halogen lamps and white fluorescent lamps
• 4000k -5000k is Cool White and is produced by cool white fluorescents
• 5000k – 6000k is known as Daylight which can be found in natural LED lamps and daylight fluorescent lamps.
For some it can be a little confusing when confronted with the notion that the higher the colour temperature the cooler the light produced and the lower the colour temperature, the warmer the light, this theory put simply is due to the fact that lighting temperature is ruled more by the psychological (visual) effect of lighting on a room as opposed to standard temperature readings and the mathematics behind these calculations are mind-bending.
Now that we know about all the technical and scientific properties of lighting temperature, let us look at how to make it work for you.
The addition of warm lighting can give a room an overall cosy, welcoming and relaxing feel, ideal for the living room, dining rooms in your home as well as the lounge and dining area of bar or restaurants. Cool lighting on the other hand is great for areas such as the kitchen, office, garage and other places where we have to focus and concentrate. Both warm and cool light produce what is commonly known as white light however warm light boasts a sunny, slightly orange tinge in its glow whereas cool light emits an icy radiating bluish white to give the room a real sharpness. Warm lighting is produced more by high pressure sodium lamps and cooler light is produced by high pressure mercury lamps.
Typically, fluorescent lamps offer the greatest range of colour temperature as both warm and cool lamps can be found with a fluorescent make up. However, incandescent lamps are primarily the producers of standard warm light which flatter skin tones and prove to be visually appealing. Halogen lamps also provide predominantly warm light which was more perceivable intensity than a common tungsten lamp producing a whiter light to give colours a much sharper appearance.
Taking the time to examine your options in regard to lighting colour temperature can be very rewarding especially if you are trying to generate a certain mood for a certain room and get the most from your lighting fixtures.
