Color Temperature (CCT) in LED Lighting

CCT is the abbreviation of Color Temperature

Color temperature in absolute temperature (K), is to a standard blackbody (such as platinum) heated, the temperature rises to a certain degree of color began to red, orange, yellow, green, blue, indigo blue purple, violet, gradual change, using the change characteristics of light color, the light source the light of the light color and black color at the same time, we call blackbody temperature at the time of the light source color temperature. When the color temperature is around 3000K, the light color is yellowish. When the color temperature is above 5000K, the light color is bluish. The light of different color temperature has different lighting and visual effect. Different color temperatures correspond to different colors of light as shown below. Different wavelengths give the human eye different color perception, from red, orange, yellow, green, blue, indigo (blue violet), purple. The sensitivity of the eye varies strongly with wavelength.

Under good lighting conditions, the eye is 20 times more sensitive to light at 550nm (yellow) than red or blue. This is also why most car fog lamps and street lamps use yellow light is an important reason. Color temperature is a measure of color temperature, not the brightness of the lamp. The color temperature of halogen lamps can range from 2300K to 7000K; HID lamp color temperature from 4200K to more than 8000K; The higher the color temperature of the lamp, the less it penetrates fog and rain. Big manufacturers such as Philips have so far only produced xenon lamps with a maximum colour temperature of 6000K. The following is the performance of different color temperatures:
Light color warm light effect
3000K yellow light, strong penetration
4200K white with yellow, original car with xenon lamp
5000K light all white, maximum European standard color temperature
6000K light all white, slightly blue
Day in the sun at 6500K
7000-8000K white is obviously bluish
Blue light above 8000K, penetration extreme difference recommended about 6000K color temperature is just the whitest slightly start to blue color temperature, the human eye is easy to accept, not easy to fatigue, improve safety, while halogen lamp is poor.