What is the three-point exposure method in photography?

First of all, it is not exposure, it is lighting! It doesn't matter if you're not a professional photographer! )

Three-point light distribution method is the setting process of main light, auxiliary light (auxiliary light) and backlight, which is called "light distribution" for short. Although a complex scene is illuminated by 100 lighting technicians, there will be 100 different schemes and effects, but everyone will abide by several principles of lighting. For indoor renderings and indoor photography, there is a famous and classic lighting theory, which is "three-point lighting". The author briefly describes here:

Generally, the main light is directed at the object at the position of 30 or 45 degrees behind the camera, which makes the object produce lighting effects and shadow. The light of the main light must be linked to the shadow effect, and choose a shadow map or something. The light intensity is slightly higher. The higher the intensity, the more obvious the shadow. It is usually used to illuminate the main object in the scene and its surrounding area, and project the main object. The main relationship between light and shade is determined by the main light, including the direction of projection. The task of the main lamp can also be completed with several lamps as needed. If the main light is in the position of 1.5 degrees to 30 degrees, it is said to be smooth; At the position of 45 degrees to 90 degrees, it is called sidelight; It becomes a side backlight at the position of 90 degrees to 120 degrees. The main light is usually made of spotlights. I like to set the brightness of the main light around 2 40.

Auxiliary light, also called auxiliary light. The fan-shaped reflector is illuminated by spotlight to form a uniform and indirect soft light source, which can fill the shadow area and scene area missed by the main light, reconcile the contrast between light and dark areas, and form a sense of depth of field and layering. In addition, this wide and uniform light distribution makes it lay the background color for the scene and define the tone of the scene. In order to achieve the effect of soft lighting, the brightness of the auxiliary light is usually only 5 0%-80% of that of the main light, which is also 30 or 45 degrees behind the camera, but on the other side of the main light, the main light can't reach the object. The function is to illuminate the dark side that the main light can't reach, and at the same time assist the main light. Make the shadow surface of the main light not close to each other. Be careful not to turn on the shadow option. At the same time, the strength is relatively weak. Usually not more than 0.5,

Backlight, behind the object, hit a floodlight with the light in the opposite direction to soften the main light and auxiliary light. The intensity of soft light should also be slightly smaller. Its function is to increase the brightness of the background, thus setting off the subject and separating the subject object from the background. Generally, floodlights are used, and the brightness should be dark but not too bright.

The following figure is a simple schematic diagram of lighting settings in this area.

The light distribution sequence is: 1) First, determine the position and intensity of the main light; 2) determining the intensity and angle of the auxiliary light; 3) Equipped with background lights and decorative lights. The light distribution effect produced in this way should be clear in priority and complement each other.

There are several places that need special attention when lighting:

1) The lighting should be exquisite but not excessive. Too many lights make the work process messy and difficult to handle, and the display and rendering speed will also be seriously affected. Only the necessary lights can be kept. In addition, we should pay attention to the use of light projection, shadow mapping and material mapping, and it is best to use mapping where light can be replaced by mapping. For example, it is much more convenient and effective to show the light in the window when you look from the outside at night than to simulate it with lights. Don't distribute light casually, otherwise the success rate will be very low. For unnecessary lights, we must resolutely not keep them.

2) The lighting should reflect the light and shade distribution of the scene, and it should be hierarchical, and all lighting should not be treated equally. Choose different kinds of lights as needed, such as spotlights or floodlights; Decide whether to project the density of light and shadow as needed; Determine the brightness and contrast of the light as needed. If we want to achieve a more realistic effect, we must make some efforts in light attenuation. You can temporarily turn off some lights to eliminate interference and set other lights better.

3) You should know that the lights in MAX can be surreal. We should learn to use the "exclusion" and "inclusion" functions of light to see whether absolute lighting can illuminate or project an object. For example, in order to simulate the lighting and projection effect of candlelight, we usually place a floodlight at the wick of the candle. If this lamp doesn't project the candle body, the big shadow produced by the candle body on the desktop may give us a headache for half a day. In architectural renderings, the method of "exclusion" is often used to make lights not produce lighting or projection effects on some objects.

4) Lighting should follow the process from theme to part and from simple to complex. For the formation of lighting effect, we should first adjust the angle to set the main style, and then adjust the characteristics of lighting attenuation to enhance the sense of reality. Finally, adjust the color of the light and change the details. If you really want to simulate the effect of natural light, you must also have a deep understanding of natural light sources. Reading more books and doing more experiments will help. The lighting used in different occasions is also different. In the production of indoor renderings, in order to show a gorgeous effect, some main lights are often set to light orange, which can achieve the effect that materials are not easy to achieve.

In short, it is only a matter of time before you practice more and dare to practice and master the essence of running out of light.