Since the creation of the stage, stage lighting has become an integral part of the stage. Stage lighting highlights the four elements of vision, realism, aesthetics and expression. It has evolved over the years. It has gradually developed into today's more complete and advanced lighting system. The first boom in theater occurred more than two thousand years ago in ancient Greece. At that time, theaters were open-air or semi-open-air. The lighting of the stage relies on the huge "lamp" in the sky, the sun, so it can only be performed during the day. The need for night rest and entertainment, open-air performances are susceptible to weather and other objective drawbacks and the development of drama make stage lighting a problem that people must solve.

    The success of the performance lighting design is marked by the proper handling of the stage lighting. Stage lighting should not only illuminate the actors and allow the audience to see their facial expressions, demeanor and movements, but more importantly, make full use of lighting technology, mobilize lighting operations and other means to strengthen the artistic effect, so that the audience has a sense of immersion.

Stage lighting is mainly produced by the combination of computer lamps and other lamps, which is a comprehensive performance through different modeling scenes, different color changes, different viewing angles, horizontal and vertical light angles, speed and slow, strobe speed and slow, aperture size changes, focal length changes and so on. Then, before understanding stage lighting technology, it is essential to master these basics:

First, visible light 

Light is radiant energy that propagates in the form of electromagnetic waves by electricity. The wavelength range of electromagnetic wave radiation is very wide, and only this part of radiation with a wavelength of 380~760nm can cause light vision, which is called visible light. Light with a wavelength shorter than 380nm is ultraviolet, X-ray, γ ray; Light longer than 760nm is infrared, radio waves, etc., which cannot produce light vision to the human eye, that is, cannot see. Therefore, light is an objectively existing energy and is closely related to people's subjective feelings. 

Second, the classification of colors 

Colors can be divided into two categories: non-color and colored. Non-color refers to white, light gray, gray to dark gray, until black, called white and black series. Pure white is an ideal object with complete light reflection with a reflectivity of 1; Pure black is ideal for non-reflective objects with a reflectivity of 0. Therefore, the non-color white-black series represents the change in the reflectivity of the object to light. We know that light reflectivity is proportional to brightness, and indoor white walls and ceilings can get higher brightness. Color refers to a variety of colors other than the white and black series. Color has three characteristics: hue, brightness and saturation, called the three elements of color. 

Hue is the color that represents the presentation. That is, the names of various colors, such as red, green, blue, etc. It is related to the wavelength of light. Lightness (brightness) is an indication of how bright a color is. The brightness of different hues is different, even if the same tone is affected by the nature of the surface of the object and the intensity of light, it will produce differences in light and dark, and shade. If it is also yellow, there can be light yellow, medium yellow, dark yellow, etc. 

Saturation (chrominance) indicates the depth (intensity) of a color, and can also be said to be the purity and vividness of the color. The higher the saturation, the darker (dense) the color appears, and the various monochromatic lights in visible light are the most saturated colors. When more white light is incorporated into a spectral color, the more unsaturated it becomes. For example, red light is more saturated than pink light because pink light is mixed with white light. Generally speaking, in the same hue, when the brightness changes, the saturation also changes, but the increase or decrease of brightness decreases its saturation, and the saturation (purity) is the largest only when the brightness is moderate. However, it always feels that the colors with high brightness always look brighter.

Third, three primary colors and color matching methods 

Red, green, and blue are called the three primary colors. These three colors are mixed in different proportions to produce a variety of colors. There are two basic methods of color mixing: additive mixing and subtractive mixing. 

The so-called additive color mixing is that when different colors of light are mixed, they add their respective parts of the spectrum together, resulting in a new method of mixing colors. Indicates the color relationship of the photoadditive color mix. Red, green, and blue can be obtained when the three primary colors of light are mixed in equal amounts:

Red light + green light = yellow light green light + blue light = blue light 

Green light + red light = magenta light red light + green light + blue light = white light

If the three primary colors are not mixed with equal amounts, various intermediate colors can be obtained, such as: 

More red light + less green light = orange light 

More red light + less blue light = pink light

Subtractive color mixing is a method in which different colors are mixed and each selectively absorbs their corresponding part of the spectrum from the incident light to produce a synthetic color effect. If any two colors of light can be added together to produce white light, these two colors of light are called complementary colors (complementary colors). For example, yellow and blue are complementary colors, cyan and red are complementary colors, and magenta and green are complementary colors. Therefore, yellow, cyan, and magenta are respectively called reduced blue, reduced red, and reduced green, which means that the three complementary colors are made by subtracting a corresponding primary color from white light. Therefore, yellow, cyan and magenta can be called the three primary colors of the subtractive method.

When the three subtractive primary colors of yellow, magenta, and cyan overlap together, black will be produced. In the process of subtractive color method, the density changes of the three subtractive primary colors control the absorption ratio of red, green and blue, so as to obtain various mixed colors, which can achieve the same effect as additive color mixing.

Fourth, color and vision 

Color will give people a sense of warmth and coldness, a sense of distance, a sense of size and weight, and often make people associate, thus forming different psychological effects, which are people's long-term formed visual habits. 

Colors can generally be divided into three categories: cool, warm and neutral (intermediate). The coldness and warmth of colors are divided according to the visual reactions and psychological associations caused by various colors to people. Red reminds people of the heat of fire, which creates a feeling of warmth, called warm color. Blue reminds people of cold water and gives people a cold feeling, so it is called cold color. Purple and green are lukewarm and neutral colors. Different colors can affect the size of the appearance of an object. If you put some objects of the same size of different colors together, the visual perception will produce a light white object. Dark black objects are small. In general, white objects look the largest, black objects look the smallest, and yellow objects are larger, followed by green, red, and blue. 

People's visual habits of color also produce a sense of distance. Objects of different colors give different visual perceptions at the same distance. Warm colors give people the feeling of moving forward, and cool colors seem to move backwards away. And the sense of distance that color gives is also affected by the background tone. For example, when white is the background, blue looks closer; With black as the background, red looks closest, followed by orange, yellow, green, blue, and purple. Using this feature can help us create an illusion effect of color stereoscopic and distance. 

The sense of weight and heaviness of color is also a long-term visual habit formed by people. It is generally believed that white is the lightest and black is the heaviest. Among the three primary colors, green is the lightest, blue is the heaviest, and red is centered. There are two kinds of primary colors and light mixed in equal amounts to form colors, light colors with light colors, heavy colors with heavy colors. The weight of color is not only expressed by brightness and purity, but also by the size of the area that color occupies in the picture. Colors that are larger in area appear heavier and attract more attention than colors with a small area.