The color of stage lighting mainly comes from two ways

The color of stage lighting mainly comes from two ways: the light color of the electro-optic original and the light color caused by the additional color filter of the electric light source (or lamp).

First, the light color of the electric light source and its spectral analysis

In the stage lighting, all kinds of electric light sources are displayed in a variety of colors, and their colors are unified by the corresponding color temperature or correlated color temperature. The radiation temperature of the black body is used to quantitatively and scientifically express the light color of the light source, and the physiology is expressed digitally. The visual volume on the upper and psychological level is a big improvement.

There are two main types of electric light sources for stage lighting: thermal radiation light sources and gas discharge light sources. Types of thermal radiation light sources include: tungsten halogen lamps (halogen lamps), steamed aluminum bulbs, incandescent lamps, etc., and types of gas discharge lamps include: xenon lamps, metal halide lamps, fluorescent lamps, etc. They have their own different relative energy distributions of spectral radiation, and usually show different light and color effects after stimulating the human eye. But there is also the phenomenon of "metamerism", that is, the light published by the relative energy of different spectra can also cause the same color vision, or the same light color may also have different spectral relative energy distributions.

The relative energy distribution of the spectrum of a fluorescent lamp (3200K) and the tungsten halogen bulb (3200K), and the relative energy distribution of the spectrum of a fluorescent lamp (5500K) and daylight (5500K). Interpreting these four spectral lines can lead to insights as follows:

1. Different lights have different spectral relative energy distributions, presenting different light colors, and are labeled with different color temperatures of 3200KT5500K.

2. The phenomenon of metamerism exists objectively. The two light sources have the same color temperature, but the relative energy distribution of the spectra of the two are not exactly the same.

3. The relative energy ratio of blue and red light in the spectral distribution of a light source with a color temperature of 3200K is small, while the relative energy ratio of blue and red light in the spectral distribution of a light source with a color temperature of 5500K has greatly increased.

4. The spectral relative energy distribution curve of halogen tungsten lamp and daylight is continuous and smooth transition, while the spectral relative energy distribution curve of fluorescent lamp has several peaks, and there are several strongly radiating line spectra between them. They are of several kinds. Characteristic spectral lines of phosphor chemical elements.

Although the trend of the spectrally connected energy distribution curve of the fluorescent lamp and the corresponding halogen lamp or daylight is roughly the same, the details of the spectral distribution are still different, and the difference in some bands is still very large. Although they are marked with the same color temperature of 3200K or 5500K, there is still a difference between the two behind them:

(1) Tungsten halogen lamps, the sun, and black bodies are all heat radiation light sources. Their chromaticity points are on the blackbody locus of the chromaticity diagram. Unlike black bodies, fluorescent lamps are gas discharge lamps, and their chromaticity points deviate. The blackbody locus just shows that it is the closest to the 3200K or 5500K chromaticity point, so it is marked with a color temperature of 3200K or 5500K. In order to distinguish this difference between the two, the color of the gas discharge light source is called "correlated color temperature".

(2) Thermal radiation light sources and gas discharge light sources with the same color temperature do not have the same color rendering properties. Because fluorescent lamps have significant linear spectral distribution characteristics, their color rendering index is generally lower than that of thermal radiation light sources with the same color temperature.

Dysprosium lamp (a kind of metal halide lamp) spectral relative energy distribution curve, it is obvious that the entire spectral range is composed of continuous spectrum and sandwiched between several strong spectral radiation line spectra, the relative proportion of blue and red light Higher. The color temperature of the dysprosium lamp is between 5000K-600K, and its spectral distribution is similar to that of daylight, but its color rendering is not as good as daylight, and its color rendering index is between 80-90. It is a gas discharge lamp with high color temperature, high color rendering and high luminous efficiency, which fully meets the technical requirements of the stage and film and television lighting fields, and shows more and more broad application prospects.

The relative energy distribution curve of the xenon lamp spectrum is very close to that of sunlight. The entire spectrum is a continuous spectrum, with only a small peak around 480nm, which has stronger radiation energy. It is not difficult to infer from this: Xenon lamp is also a high color temperature electric light source, the color temperature is about 5500K, has excellent color rendering performance, and its color rendering index can be as high as 94. The excellent comprehensive performance of the xenon lamp is outstanding among gas discharge lamps. Its research and development and application in high luminosity and long-range follow-up lamps, projection lamps, and floodlights have already come to fruition.

When the stage lights are dimmed gradually, the light color and color temperature of the light source will change accordingly, indicating that the relative energy distribution of its spectral radiation has changed. For example, when the tungsten halogen lamp is dimmed from the rated voltage value, the light parameters change law is: the brightness and color temperature gradually decrease, and the light color gradually drifts to the red direction. On the contrary, when the working voltage increases, the brightness and color temperature will both increase. , The light color gradually changes from red to yellow and white. When the color chip is arranged in front of the lamp, when using dimming or non-rated voltage working conditions, the color temperature change of the light source should be considered and the general trend of the color light change.

Second, color light and its spectral analysis

The color of the light may be converted. The simplest and most practical method is to configure a special color filter in front of the light source (or lamp) to obtain a new light color.

There are two types of color filters: color temperature conversion filters (or color temperature correction filters) and color light filters. The color filter has the optical characteristics of selective absorption of light. For example, the color filter medium has different proportions of absorption of light of each wavelength in the visible spectrum, which changes the relative energy distribution of the light source's spectrum, and the transmitted light stimulates the human eye. Different from the light color effect of the light source. Color filters of different chromaticities have their own different spectral transmittance curves, conveying their different optical characteristics of selective absorption.