What is the color temperature?
Color temperature is a unit of measure that expresses the color components contained in light. Theoretically, the color temperature refers to the color that the absolute black body appears after it is heated from absolute zero (-273 ° C). Black body after heating. Gradually change from black to red, turn yellow, white, and finally emit blue light. When heated to a certain temperature, the spectral components contained in the light emitted by the black body. It is called the color temperature at this temperature, and the unit of measurement is K (Kelvin).
If the light emitted by a light source has the same spectral components as the light emitted by the black body at a certain temperature, it is called a K color temperature. For example, the color of the light emitted by a 100 W bulb is the same as that of an absolute black body at 2527 ° C, then the color temperature of the light emitted by this bulb is: (2527 + 273) K = 2800K. Color temperature is a temperature measurement method that is commonly used in the fields of physics and astronomy.
This concept is based on a fictional black object that emits different colors of light when heated to different temperatures, and its objects appear in different colors. Just like when heating an iron block, the iron block turns red first, then yellow, and finally white. In the stage lighting equipment, the colors presented by the lighting effects are represented by color temperature.
The color temperature calibrated using this method is the opposite of what the general public thinks is warm and cold. For example, people usually feel that red, orange and yellow are warmer and white and blue are colder.
In fact, the red color temperature is the lowest, and then gradually increases The colors are orange, yellow, white, and blue, and blue is the highest color temperature. When shooting with natural light, the color temperature of the photos is different because the color temperature of the light is not the same in different time periods. For example, when shooting under a clear blue sky, the color temperature of the light is high, so the picture is colder.
If you shoot at dusk, the color temperature of the light is low, and the picture is warmer. When shooting with artificial light, different types of light sources may occur, and the color tone of the photos will be different.
Position and role of color temperature
So how to locate the color temperature? Generally, from 10 noon to 2 pm, the sky is clear and cloudless. In the absence of direct sunlight, the standard daylight is about 5200 ~ 5500K. When the sun rises in the morning, the color temperature is about 3200K.
The color temperature of general tungsten filament lamps, tungsten filament lamps used for black and white photos in photo studios, and ordinary ordinary light bulbs is about 2800K. Because the color temperature is low, the photos taken in this case will feel warmer and yellower after being enlarged. The color temperature of general fluorescent lamps is around 7200 ~ 8500K, so photos taken under fluorescent lamps will be cyan.
The current stage lighting equipment generally uses 3200K and 5600K, so that people can shoot people clearly. For different shooting requirements, choose different lights, for those with high shooting requirements, you can choose lights with gradient color temperature.
The color temperature of the TV camera is 3200K, and the color rendering index is required to be above 90. The color temperature of the light source of the conference room lamps is generally 3200K / 4000K / 5600K. Among them, the 4000K color temperature is commonly used, which can meet the requirements of the free-range video camera to the light source Technical requirements …
Different scenes and different shooting requirements also require different color temperatures of the lights. After understanding the color temperature of the lamps and the use of the scene, you can better arrange the stage lighting scheme.