Sensitivity of seven weapons in photography introduction

White balance literally means white balance. The biggest use in SLR cameras is to restore white to white.

Color temperature (naked encyclopedia definition): The so-called color temperature, in short, is to use Kelvin temperature (K) to express color quantitatively. Kelvin, a famous British physicist, believes that if a blackbody substance can absorb all the heat falling on it without loss and release all the energy generated by heat in the form of "light", then it will become different colors due to the level of heat. For example, the thermal stress on the black body will turn dark red when it is equivalent to 500-550℃, yellow when it reaches1050-1150℃, and blue when the temperature continues to rise. The color composition of the light source corresponds to the thermal temperature of the blackbody, and the color temperature of any light is equivalent to the "temperature" when the blackbody emits the same color. This temperature is used to indicate that a certain color light is different from other characteristics, that is, the color temperature. In the process of striking iron, black iron gradually turns red in the furnace temperature, which is the best example of blackbody theory.

Performance of color temperature phenomenon in daily life: Because of the low color temperature in tungsten lamp, the light emitted is yellow, and different street lamps also emit different colors of light. The flame of natural gas is blue because of its high color temperature. At noon, the color temperature under direct sunlight is about 5600 K, and the color temperature on cloudy days is about 6200K K. At sunrise or sunset, the color temperature is about 2000K, and the color temperature of candlelight is about1000 K. At this time, we can easily find a rule: the higher the color temperature, the bluer the light color; The lower the color temperature, the redder it is.

On a cloudy day, the color temperature of the lake is high and blue (the picture below shows the work of Guangying 17585):

The definition of white balance has been explained. Only by using white balance correctly can white be turned into white. Generally, digital cameras have a variety of white balance modes to meet the needs of normal color reproduction under different light sources. Common white balance modes are: automatic, sunlight, cloudy, cloudy, tungsten lamp (incandescent lamp), flash, fluorescent lamp, color temperature value, etc.

In some circumstances, the commonly used white balance mode can't meet the professional needs, so you need the help of color temperature. Different environments have different color temperature values. As long as the correct color temperature value is used, the correct color reproduction can be obtained.

Sunny sunshine 5400k cloudy day 6000k shadow 7000k flash before sunset 5600k after sunset 3800k before dawn 3200k sunny grassland 5800k kerosene lamp 2200k warm yellow energy-saving lamp 2600k cold white energy-saving lamp 4000k incandescent lamp 2800k cloudy day snow 6000k blue sky snow 6800k indoor natural light: morning 10:00 5300k noon 5300k. In this case, many cameras provide manual presets.

To get the most accurate color temperature, it is to use manual preset white balance. Manual white balance generally uses white paper or 18% gray card (because the paper color is different, it is recommended to use professional color card. ) put it under a light source, and then measure the white paper with a camera to determine the white balance. Please refer to the camera manual for specific setting methods.

In some outdoor environments, when there are multiple light sources, there will be multiple color temperatures. At this time, only the main light source can be given priority to. For example, an indoor desk by the window, where the sun shines in, is the color temperature of the sun; There is light bulb lighting on the table, which is warm; In addition, there are fluorescent lamps in the room, and the temperature is blue. It is impossible for us to calibrate all the cameras accurately. So what should we do? The first method is based on the main light source, and the second is to set off the background light of the atmosphere, such as taking a desk and balancing it with a white light bulb; If you want to shoot the softness of the side light outside the window, use daylight white to balance it.

For a long time, as a photographer or art lover, if you dare to break the routine, you will get unexpected gains.

Application higher than ambient color temperature: As shown in the figure, the color temperature in the evening is low (the color temperature in the evening is 3200 K). At this time, if you use a color temperature value higher than the color temperature in the evening, you will get a warm evening photo, which can better express and compare the color in the evening with the gorgeous glow of the fire cloud. (The picture below shows Tommy Tianyu's work)

The above-mentioned intentional use of the wrong color temperature value has resulted in a portrait with cool colors and a night scene photo with warm colors. Then we can further upgrade the order, use light sources with different color temperature values, and get photos that make cold warm, warm cold, and cold and warm contrast.

As shown in the figure, the combination of two different color temperatures, the cave in the shadow (color temperature is 6800K) and the torch (color temperature is 2200K), makes the picture produce a cold and warm contrast effect.

As shown in the figure: (The picture below shows Tobias Ryser's work)

As shown: (The picture below shows Eric Paré)