​Use light source color temperature to build moving wedding photos

Light, about shadow, about color, about emotional appeal and atmosphere. Light is always the most fundamental and important thing in photography. When it comes to color, I can't jump out of the light. Color depends not only on the object itself, but also on the light source and the viewer. How can the colors of the main elements in the environment be accurately controlled in the picture and objectively reproduced or subjectively expressed in the picture according to the creator's intention?

This paper will systematically describe the concept and principle of light source color temperature and white balance adjustment, and with a wealth of examples to analyze how to skillfully use the difference of light source color temperature to set white balance parameters in the process of wedding and travel shooting, to achieve the ideal effect, create a moving picture.

Light source color temperature and white balance adjustment

1. The color temperature is specific to the light source and is used to indicate the spectral composition

Color Temperature, also known as "light source Color Temperature", describes the spectral composition of the thermal radiation light source and can be expressed in terms of absolute Temperature K (Kelvin). Need to explain is, color temperature is not the object color sign, also is not brightness sign, it only shows the change of spectral composition of thermal radiation light source. When the spectral composition of the actual light source is consistent or close to that of the complete radiator (also known as the absolute black body) at a certain temperature, the temperature of the complete radiator is used to represent the spectral composition of the actual light source.

In 1848, British physicist Kelvin discovered the relationship between light color and temperature in a physics experiment. He heated the black body (also known as the absolute black body, or the complete radiator) in a sealed container. Starting from the absolute zero (-273.16°C), the color temperature increased by 1°K for every 1°C increase in temperature. Therefore, people later used the first capital letter K of the name Kelvin as the symbol unit of the color temperature of light source.

As can be seen from the above table, high or low color temperature means that the proportion of spectral components in the light source is different. When the color temperature of the light source is 5500K, the ratio of red light, green light and blue light in the spectral components is roughly the same, and the light emitted then is white light in people's visual perception, and the color rendering index is as high as 100. When the color temperature of the light source is lower than 5500K, the green light component in the spectral component of the light source remains unchanged, but the ratio of red light component is significantly higher than that of blue light component. With the gradual decrease of the color temperature value of the light source, the proportion of red component increases continuously, while the proportion of blue component decreases gradually. On the contrary, when the color temperature of the light source is higher than 5500K, the green light component in the spectral component remains unchanged, but the proportion of red light component decreases gradually, while that of blue light increases gradually. Characteristics of color temperature: the height of the color temperature of the light source indicates the different spectral components. The lower the color temperature of the light source, the more red components in the light source. The higher the color temperature of the light source, the bluer in the light source.

2. White balance is used for image acquisition equipment to match spectral components of light source and ensure accurate color restoration

White Balance adjustment refers to the adjustment of the mixture ratio of three-color electrical signals of the digital image acquisition equipment under the same light source to make it consistent with the spectral components of the actual light source, so that the color of the scene can be normally reproduced or the best tonal effect can be formed according to the creation intention.

The significance of white balance is to ensure that the image acquisition equipment can restore white objects to white under any light source. For the phenomenon of color deviation in the shooting under a specific light source, it can be corrected by adjusting the white balance offset, or it can be adjusted to achieve a unique artistic color rendering effect. Specific methods are varied.

Relationship between light source color temperature and white balance

1. When the color temperature of the light source is consistent with the balanced color temperature calibrated by the camera (i.e. the white balance), the color of the scene is restored normally in the picture.

2. When the color temperature of the light source is lower than the balanced color temperature calibrated by the camera, the color tone of the picture is orange-red.

3. When the color temperature of the light source is higher than the balanced color temperature calibrated by the camera, the picture tone is bluish blue.

Ii. Control the color balance of the picture during shooting

1. Some scenarios where automatic white balance is not recommended

The camera's automatic white balance feature isn't absolutely accurate, nor is it smart enough to know all of your creative ideas. When shooting in an environment with low or high color temperature, if automatic white balance is simply used, all scenery will tend to the effect under the midday sun, which will erase the original color sense and atmosphere of the environment.

For shots with too much white or black area, we will correct the deviation of the automatic metering system by adjusting the exposure compensation when using the automatic exposure gear, or we will change the manual exposure directly. Similarly, when shooting large scenes with high or low color temperature, it is suggested to change to manual white balance, or choose different white balance positions according to the difference of specific scenes, so as to take the psychological feelings brought by colors into consideration in shooting. Sun, for example, in the evening sunset colour temperature is very low, can make scenery with a layer of golden yarn dreamy, then if you want to do the whole environment atmosphere, to let the camera's white balance parameter is higher than the actual light source color temperature values, with the white balance parameters of the 5500 k, for example, around 3000 k to photograph the sunset scene, can get warm yellow tones. If you shoot in the snow or at night, to highlight the feeling of cold, you will generally make the overall tone of the picture bluer. At this time, the parameters of white balance will have to be lower than the actual ambient light color temperature to present the cold tone.

It should be noted that the skin tone of the characters is usually not processed into cold tone. In high color temperature environment, to make the environment appear cold, the low-color temperature light source is often used as the character's supplementary light, and the white balance value is set according to the supplementary light source. In this way, the whole scene will be bluish, while the character's skin tone is normal. When shooting the contrast between warm and cold of such a large scene, the output power of the flash used to fill the light is often difficult to achieve the purpose of balancing the character's skin color, and the general assistant will fill the light in a close range. It can be used to erase the supplementary light source in the later stage by photographing an empty scene of the same location.

△ About 4 p.m. Mont Blanc, Switzerland, when the sky was not so dark in the picture, in order to reflect the cold feeling of Mont Blanc, I adjusted the white balance of the camera to the fluorescent light, dim exposure, in order to highlight the picture levels. Let the assistant get close to the new person and illuminate the character with a flash with orange patches. When the camera is still, the assistant leaves for another shot, so that the assistant can be repaired later.

Around 6 p.m., this was the last photo of the wedding location shot in the community of the couple's wedding house. The first thing That came to my mind was to use the flash and orange patches to fill the light from one side, rather than to fill the light, to create the atmosphere. It was a sunny evening, and the exposure could be done with full aperture, but the light would be a little flat, so I wanted to enhance the warmth and create an atmosphere by adding direct light at low color temperatures.

Backlight shooting, in order to highlight the overall atmosphere at that time, no supplementary light was given to the characters. The color temperature of the sun is low before sunset. If automatic white balance is used, the warm feeling will be eliminated. Manually adjust the white balance and set it at about 5500K, then the warm tone screen can be achieved. The later period can appropriately pressure the dark sky, brightens the character.

2, the construction of a number of warm and cold contrast techniques

Building contrast is a kind of artistic expression technique often used to shoot wedding, the vast majority of the contrast effect is the use of different light source color temperature difference in the environment to achieve. Here are a few examples.

Before sunrise and after sunset, the color temperature of the sky is on the high side, and the metropolis is blue and purple. At this time, the light ratio of sky light and ground light is roughly 1:1, which shows in the camera that the sky and buildings have details and colors, and the overall effect is gorgeous and dreamy. The high color of sky light and the low color temperature of ground light provide an excellent contrast effect. When the character is placed in this environment, what needs to be done is to control the color temperature of the supplementary light source to make the character stand out while the skin tone is normal (As shown in Figure 4). On rainy days or evenings without the sun, the overall environment color temperature is too high, so the low-color temperature light source is used as the main light of the character. The white balance parameter is set according to the parameter of the light source, and the soft contrast between the cold and warm of the picture can also be easily realized (As shown in Figure 5).

Shortly after the sun sets, ground lights flash, making this the perfect "density moment" for a shot outside. The ambient light is just right. What we need to do is make the characters stand out. I put the flash with orange patches on the back of the bride to create a silhouette. It should be noted that the ambient light must be taken into account in this shooting method. It is too early and the day is too bright to achieve this effect with the full light output of the flash. It is too dark for the sky to present this "density blue".

The beach of Hue Hin, Thailand, cloudy day, around 5 o 'clock in the evening, the environment light dim, soft, contrast is not strong, color temperature is relatively high. This photo is a bonus, capturing an emotional moment. Quickly adjust the white balance of the camera to the fluorescent light mode, and add orange pieces to the ceiling flash to play back, softening the effect of the light on the characters, while creating a contrast between the cold environment and warm skin color, which enhances the emotional appeal.

When the characters are in the room, the main light is the window light, we can adjust the white balance to the daylight mode, the character's skin color returns to normal, use the low color temperature light source to create interesting foreground, form the warm tone atmosphere. (As shown in FIG. 7) You can also choose to use the low-color and warm light source as the main light of the character. The white balance parameter is lowered accordingly, so that the shadow inside the house and outside the window will naturally present a cool atmosphere. (As shown in FIG. 6) It can also match the existing light source in the environment to fill the light for the character and create a sense of atmosphere of environmental light. At this time, the character's skin color can be appropriately warm. (See Figure 8)

The bride sits at the window of the wedding room, and it is getting dark after four o 'clock in the afternoon. I intended to use the window light to shoot, but the contrast was not strong and the color was flat, so I manually set the white balance of the camera at 3950K, and the environment presented a light and cold tone. In order to ensure that the character's skin color returns to normal, I used a torch of 2900K to fill the light for the bride. The unlit part naturally presents cold colors, and the contrast between light and dark and warm and cold in the picture is presented. The later period adjusts appropriately, aggrandizement colorific aesthetic feeling.

On the right, there is a window where the bride is standing in bright sunshine on a normal exposure based on the character's face. The indoor environment is naturally darkened. In order to increase the beauty and interest of the picture, I used a flashlight with a color temperature of about 2900K to illuminate the vase in the close shot, and used the shifting lens to shoot and adjust the focal plane, so that the figures and flowers were clear at the same time. The warm flowers in the close shot were in perfect harmony with the natural figures in the distance.

Delta bride standing on the stairs in the home, big droplight is the main source of the house, I use flash light with orange slices from figure according to the bride to the left of the distance, in order to let the person skin close to the ambient light, side light strengthens the character's facial contour, slant warm color droplight with color close, create a beautiful warm color light environment image. The color temperature of the indoor light source is 3200K, which forms a contrast with the outdoor sunlight environment of 5500K.

3. Multicoloured spots outside the coke are the best atmosphere maker

Make use of the difference of light color temperature, create interesting foreground or background, will make the picture presents a wonderful and dreamy color atmosphere. To achieve this effect, you need to ensure the following three elements: first, there is different color temperature of the light in the picture; secondly, there should be bright "points" in the picture, which will become a point light source under the illumination (or themselves). Finally, shoot with a wide aperture, turning the bright spot outside the focus into a dreamy spot.

In addition, we should also pay attention to the following points. If the point light source is not self-luminous, the shooting Angle is mostly backlight and side backlight. The blur effect is related to the relative position of the focal plane. To highlight bright spots, try to choose a darker background.

After the bride's new home, the door is setting off fireworks; the couple standing under the eaves of the building, the light is soft and bright. They smile at each other, and the photographer only needs to capture the couple's natural, vivid moments. Use fireworks as a foreground to create bright and warm spots of light. At the same time, the light color temperature emitted by fireworks is very low; reflecting on the human face presents a natural warm tone. No artificial light supplementation was used.

This is a rainy wedding location. A transparent umbrella and a flash light, which are commonly used by many people, illuminate the raindrops to create a dreamy atmosphere. The camera is set to automatic white balance so that the environment is not too cold. In order to make the picture more interesting, I added orange pieces in front of the flash and placed them on the wall on the right side of the painting. The Angle of the side back light illuminated the figure, drawing out the soft outline of the figure while brightening the raindrops, which brought out a warm feeling in the cold and rainy environment.

At four in the morning, the bride sat in the car in which she was to deliver her baby. It was raining outside, with raindrops all around the window and the car. Set the camera's white balance to fluorescent light, dark areas to a cold environment, and use a flash with orange patches to highlight the bride. The Angle of the flash is the key to keeping the light on the character natural and in harmony with the ambient light to avoid large contrasts. At the moment the bride got on the bus and waved, I spun the flash to the left, softening and illuminating the figure with reflected light, creating a warm, natural contrast to the surroundings in a dreamy way. The wide-angle lens fills the picture with tension, and the large aperture makes the raindrops outside the focus blur into a dreamy light spot.

The white balance of the camera was set to 3700K, so that the shaded area in front of the ring presented a light blue cool tone, and a low temperature light source was placed behind the left of the ring as a backlight, so that the ring was in an environment with alternating warm and cold colors. In order to enrich the visual expression of the picture, I sprayed water on the table, and the water droplets outside the focal point and the reflective spot of the ring and diamond made the picture dreamier.

Convenient low - color temperature-fill tool

1. Flash with orange slice. When it is commonly used in backlight, side backlight or blanking, it can also be used as contour light and front supplementary light. However, there are certain limitations when it is used. In scenes that are too bright, too dark or too large, it is difficult to exert its power due to its limited output power.

2. Warm flashlight with color temperature of 2900K. The flashlight light is not strong, the use range is not wide, but easier to control, mainly used for close shooting, to create an interesting atmosphere for the dark environment;

3. Led light with color temperature of 3200K. Usually used for front or large area lighting.

Because color temperature is low, so at this time the main purpose of the light source is not completely for the character fill light or outline the outline, to create a contrast between warm and cold, the formation of a dreamlike atmosphere, highlight the unique artistic conception, has become more factors to be considered. Any kind of light filling tool should be used in combination with the exposure of the environment. Even the front light should not be too bright. It should be integrated into the overall environment and the first principle should be the comfortable light ratio and contrast of the picture. When setting white balance, you should try your best to achieve the restoration of skin color, close to the effect under the sun, some cases can be according to the environmental light effect, appropriate slant warm.