When the color of the light emitted by the light source is the same as the color of the “black body” radiated at a certain temperature, the temperature of the “black body” becomes the color temperature of the light source.
The higher the temperature of the “black body”, the more the blue component in the spectrum and the less the red component. For example, the light color of the incandescent lamp is warm white, the color temperature is 2700 K, and the color temperature of the daylight fluorescent lamp indicates The method is 6000K.
Color temperature and brightness: Under the high color temperature light source, if the brightness is not high, it will give people a cold atmosphere; under the low color temperature light source, the high brightness will give people a kind of sultry feeling. The contrast of light color: In the same space, two kinds of led flood lights with large differences in light color are used, and the contrast will have a gradation effect. When the light color contrast is large, the light level can be obtained while obtaining the brightness level.
Because most of the light emitted by the light source is commonly known as white light, the color table temperature of the light source or the correlated color temperature is used to refer to the degree of the light color relative to white to quantify the light color performance of the light source.
According to Max Planck’s theory, a standard black body with complete absorption and radiation power is heated, and the temperature gradually increases. The black body locus on the CIE color coordinate shows that the black body is red-orange– Yellow – yellow white – white – blue and white process.
The temperature when the black body is warmed to the same or close to the light color as the light source is defined as the correlated color temperature of the light source, and the color temperature is expressed in absolute K (Kelvin, or Kelvin). (K=°C+273.15) . Therefore, when the black body is heated to red, the temperature is about 527°C, that is, 800K, and the temperature of the blackbody affects the color change.
The more bluish light color, the higher the color temperature; the lower the color temperature, the more reddish it is. The light color of the day also changes with time: the light color is 40 minutes after sunrise, the color temperature is about 3,000K, the snow is white at noon, it rises to 4,800-5,800K, and it is about 6,500K at noon on cloudy days; the light color before sunset Reddish, the color temperature dropped to about 2,200K again.
Since the correlative color temperature is actually the value of the evaluation of the light color of the light source when it is close to the light color of the light source, it is not an exact color contrast. Therefore, two light sources having the same color temperature value may have a light color appearance. There are still slight differences. With color temperature alone, it is impossible to know the color rendering ability of a light source on an object, or how well an object color is reproduced under the light source.