We all know that the standard light source is actually the reference sunlight spectral energy distribution at different times, because the spectral energy distribution has been changing at different times, so the color temperature of the sun is also changing. Let's study the color temperature of sunlight at various times!
The color temperature change of sunlight indicates: Sunrise and sunset have the following three characteristics: First, the brightness of the sun changes greatly, at sunrise, the sun rises from the horizon, and the brightness of the sun increases rapidly; at sunset, the sun slowly disappears on the horizon, and the brightness of the light decreases rapidly. Second, at sunrise and sunset, the sun's light is slanted to the ground, and because of the thicker atmosphere on the Earth's surface, the high color temperature of the shorter wavelength, such as blue light, is absorbed in large quantities, leaving behind the lower color temperature of the longer wavelength, such as yellow, red or gold. Third, the color temperature at sunrise or sunset is about 2000K, and the color temperature changes quickly. At sunrise, the color temperature becomes higher, rising rapidly from 2000K to 3500K, and the color separation temperature reaches about 5500K at noon. Cameras generally use 5600K as the color temperature of white daylight, below this value is considered as a low color temperature, which appears as yellow or orange, and above this color temperature appears as blue. In order to restore the visual impression of the sun, 5600K color temperature can be used when adjusting the white balance, which is conducive to the passage of low color temperature light lines, more to prevent the passage of high color temperature light lines, and can make the picture warm when shooting sunrise or sunset, exaggerating the orange-red hue, so that the color of the sun itself is orange-red or golden. What is the color temperature of sunlight? Description of sunlight color temperature at each time: Sunlight at sunrise 1850-2000 Sunshine half an hour after sunrise 2380-3000 3500 sunlight 1 hour after sunrise Sunrise 1 1/2 hours of sunshine 4000 Sun 4400 2 hours after sunrise Sun at 4:30 PM 4750 3:30 PM sun 5000 Noon direct sunlight 5300-5500 Uniform clouds cover the sun 6400-6900 Cloud filled sky 7500-8400 Blue sky with thin clouds 13000 Specific application of sunlight color temperature: Natural light is not the white light that our eyes perceive, and the eye works more like a camera, applying automatic white balance to everything we see. However, the film's perception of light is very different from that of the human eye - it will perceive the color of sunlight to be bluish. This is reflected in the performance of daylight type motion picture film, whose equilibrium color temperature is shown as 5500K on the color thermometer. For a film that is balanced with daylight color temperature, it is not necessary to use any color correction filters when shooting outdoors, and color balance can be achieved when shooting at a color temperature of 5500K. Daylight is actually a very bright hard light with a high Kelvin color temperature: blue light has a higher color temperature than amber light. Film emulsions are sensitive to color temperature and absorb color light in their own way, so daylight films are designed to absorb sunlight that has not been filtered through any color correction. At a color temperature of 5500K, the film naturally absorbs blue light from sunlight. The light color temperature of the steel lamp is also 5500K to match the inherent color of daylight. The use of steel lamps can assist daylight to work well on daylight type films because they have the same color temperature. In fact, add a 1/2 blue CTB filter to the tungsten lamp, and the resulting color temperature can also be close to daylight. For a photographer, playing with color temperature is as much a part of the craft as a painter. These are the "What is the color temperature of sunlight?" compiled by Jaydon. How did it change?" All content, want to know more industry information and color temperature common sense partners, you can continue to pay attention to our subsequent updates!
