choose the right color temperature

Color temperature is an important factor when considering buying LED lights. This article will tell you what color temperature is and how to choose the right one for your LED lights.

1. What is color temperature ? 

Color temperature (CCT) represents the color appearance of light from a lighting item, describing the warm (yellow appearance) or cool (blue appearance) color of a light source. CCT is measured in units of Kelvin, with higher numbers indicating bluer or "cooler" hues such as fluorescent tubes used in industrial settings (3100K to 4500K), lower numbers indicating the orange, yellower, cooler colors of old incandescent lamps Soft, "warm" tone lights (2000K to 3000K).

Explained in terms of how sunlight works, the sun changes color throughout the day, measured in degrees Kelvin. A midday reading might be 6000K, or a very bright blue-white, while at sunset the temperature might drop below 3000K for a very warm amber glow.

Correlated Color Temperature (CCT)

The technical "blackbody" definition of color temperature originally applied to incandescent light bulbs because the thermal radiation method they produce light is very similar to blackbody radiators. However, newer lighting technologies such as fluorescent lamps and LEDs do not produce light in the same way, so a method is needed to measure their light output characteristics on the same scale that everyone is accustomed to. Therefore, these light sources are assigned an adjusted measurement called correlated color temperature, which puts them on the same scale of comparison as incandescent light bulbs.

Why does the CCT go from "warm" (yellow) to "cold" (blue) while the actual temperature goes from low to high? This puzzling oddity is not only ubiquitous in photography, but everywhere the color of lighting is mentioned. "Cool" is associated with bluer colors simply because the human brain associates it with cool things like snow. On the other hand, we tend to associate "warmth" with the color of a flame or a warm theme like a campfire.

Let's take an example of a blue flame (which burns hotter than a red or yellow flame) is considered the hottest. It reminds us why "cold blue" and "red hot" are very similar to Kelvin numbers in opposite directions.

CRI, also known as Color Rendering Index, is a useful illuminance specification that predicts the potential of a light source to accurately display the color of the objects it illuminates. In color-critical applications such as operating rooms and artistic restoration, lighting sources with high color index are required.

100 is the highest "score" for having excellent color generation, revealing what can be seen in bright sunlight. So every type of  light can show color.