What is colour temperature and why does it matter?

by | 8 Nov 2021 | Knowledgebase, Lighting

Colour temperature is a way of describing the characteristics of the light your fixtures are producing. As we are looking for an easily understandable way to explain the light, it is often discussed in terms of its warmth or coolness. There is a very specific scientific definition for colour temperature developed from astrophysics, but for our purposes warmer light appears more yellow and cooler light is more blue.

Colour temperature is measured in Kelvins, using the symbol K, and this is the figure you’ll often see in the spec sheet for lighting elements. While it seems counter-intuitive with the language used, warmer colours have a lower value. Cool colours will have a temperature over 5,000K whereas warm colours will be in the range of 2,700-3,000K.

While possible, there is little point in talking about the colour temperature of greens and purples. It tends to cover light from reds all the way up to blueish white, but is most often used as a description for white light. This is important because it has a significant effect on the atmosphere you create. Warmer whites create a more relaxing atmosphere whereas cooler whites can help with concentration and productivity.

Colour temperature for white lighting is an important element for a number of applications. In theatrical lighting it can be used to provide a literal representation of times of day or more of a subjective expression of the mood being conveyed at any point. Whereas in venue installations it can help to create different kinds of atmosphere depending on what you are trying to achieve – for example a low level of warmer white light can help to give a bar a more intimate feeling.

When you move away from a world where it is the human eyes capturing the light, colour temperature becomes even more important. While human eyes can easily adapt to changing colour temperatures a camera – whether that is for broadcast or photography – needs to be told what colour light is illuminating a scene and the white balance adjusted every time the colour temperature is changed.

When there is a camera involved, colour temperature effects the way that white surfaces appear on film and in turn the balance between every colour in the shot. You want white objects to be correctly interpreted by the viewer as white, when this happens you have balanced the white and every other colour will be balanced too. 

To learn more and discuss your lighting needs, get in touch with the lighting experts at Prosound today.