Because the light emitted by most light sources is collectively referred to as white light, the color table temperature or related color temperature of the light source is used to refer to the degree of its light hue white to quantify the light color performance of the light source. According to the Max Planck theory, a standard black body with full absorption and emission capacity is heated, and the temperature gradually increases and the luminosity changes. The Black body locus on the CIE color coordinates shows the process of the black body changing from red – orange – red – yellow – yellow white – white – blue white. The temperature when the blackbody is heated to appear the same or close to the light color as the light source is defined as the relevant color temperature of the light source, called the color temperature, in absolute temperature K(Kelvin or Kelvin temperature) as a unit (K=℃+273.15). Therefore, when the blackbody is heated to be red, the temperature is about 527℃, that is, 800K, and other temperatures affect the change of light color.
The bluer the light color, the higher the color temperature; Red is the lower the color temperature. The color of the painted light also changes with time during the day: 40 minutes after sunrise, the color color is yellow, and the color temperature is 3,000 K; The noon sun is white, rising to 4,800-5,800 K; Around 6,500 K on cloudy days at noon; Before sunset, the light color turns red, and the color temperature drops to 2,200 K. The correlation color temperature of other light sources, because the correlation color temperature is in fact a blackbody radiation approaching the light color of the light source, the evaluation value of the light color performance of the light source is not an accurate color contrast, so the two light sources with the same color temperature value may still have some differences in the appearance of the light color. The color temperature alone does not allow us to know the color rendering ability of the light source to the object, or how well the color of the object is reproduced under the light source.
The correlated color temperature of different light source environments
North clear sky 8000-8500k
Cloudy days 6500-7500k
Summer noon sun 5500k
Metal halide lamp 4000-4600k
Afternoon daylight 4000k
Cool color camp light 4000-5000k
High-pressure mercury lamp 3450-3750k
Warm color camp light 2500-3000k
Halogen lamp 3000k
Tungsten lamp 2700k
High pressure sodium lamp 1950-2250k
Candle light 2000k
Different light source color temperature, light color is also different. The color temperature below 3300K has a stable atmosphere and a warm feeling; Color temperature in 3000-5000K for the middle color temperature, there is a refreshing feeling; The color temperature above 5000K has a cold feeling. Different light colors of different light sources make up the best environment.
Color temperature is how the human eye feels about luminous or white reflectors, it’s physics. A sense of the combined complexity of physical and psychological factors is also different from person to person. The color temperature can be changed in a human way on television (light emitting body) or photography (reflective body). For example, in photography, we use a 3200K white incandescent lamp (3200K), but we add a red filter on the lens to filter a little red light to make the photo look lower color temperature; In the same way, we can also reduce the red color on the TV (but too much will affect the normal red performance) to make the picture appear higher color temperature.
The preference in color temperature is determined by people, which is related to the scenery we see daily, for example, people close to the equator, the average color temperature they see daily is 11000K(8000K(dusk) ~ 17000K(noon)), so they prefer high color temperature (looks more real), on the contrary, People in higher latitudes (average color temperature of about 6000K) prefer lower color temperatures (5600K or 6500K), that is, if you use a high color temperature TV to show the Arctic landscape, it will look greener; On the contrary, if you use a low color temperature TV to watch the subtropical style, you will feel a little red.
How is the color temperature of a TV or display defined? Because the average color temperature of the scenery in China is between 8000K and 9500K throughout the year, the TV station shoots the program with the color temperature of the audience at 9300K. But Europe and the United States because of the usual color mild we have differences, with the average color temperature of about 6000K throughout the year as a reference, so when we look at those foreign films, we will find that 5600K ~ 6500K is most suitable for viewing. Of course, this difference makes us feel that when we see the computer or TV screen in Europe and the United States, the color temperature is red, warm, and some are not suitable.
People with black eyes see 9300K as white, but people with blue eyes see it as blue. People with blue eyes see it as white. People with blue eyes see it as white.
