What is color temperature?

Light is not always what it seems. Our eyes are very forgiving, so when we move from place to place everything seems normal in terms of color. So, for example, when moving from a bright daylight environment to a room lit by a candle all that will appear to change, to the naked eye, is the light level.

Color temperature is a characteristic of visible light that has important applications in lighting, photography,videography, publishing, manufacturing, astrophysics,horticulture, and other fields.

Color temperature is typically recorded in Kelvin, the unit of absolute temperature. The scale ranges from the flame of a candle at around 1900K to deep blue sky at around 10,000k as illustrated by this diagram. Cool colors like blue and white generally have color temperatures over 7000K, while warmer colors like red and orange lie around the 2000K mark. Colour control filters are broadly split up into two categories: colour conversion and light balancing filters. The strong colour conversion filters are in the 80 and 85 series and are used for large colour changes while weaker lighting balance filters fit in the 81 and 82 series and are used for making small colour adjustments.

The requirements for color temperature differ a lot in different industries. As for lighting building interiors, it is often important to take into account the color temperature of illumination. For example, a warmer (i.e., lower color temperature) light is often used in public areas to promote relaxation, while a cooler (higher color temperature) light is used to enhance concentration in offices.