When we talk about the color of an object, it refers to the color under daylight. It turns out that the color of an object is not an attribute of the object itself. The color of an object depends on two factors, one is the reflection characteristic of the object itself, and the other is the spectral distribution of the light source that illuminates it. Daylight is a source of thermal radiation, its spectrum is smooth and continuous, and is essentially equal energy distribution in the visible range. The human eye is accustomed to the color of various objects seen in daylight. Therefore, everyone thinks that the color of objects in daylight is the most "positive" and the most sense of identity. The same object will be different under sunlight and under other light sources. For example, a white cloth is white under sunlight, red under red light, and green when illuminated with green light. We still think that this piece of cloth is white, and when it is illuminated with red light or with green light, we think it is partial color. Because of this, the color rendering index is an amount that quantitatively expresses the above difference in light source. In colorimetry, the color rendering index of daylight is defined as 100 (please note that it is 100, not 100%), and the color rendering index of other light sources is lower than 100. At present, the spectral distribution of common electric light sources is more or less The spectral distribution of daylight is different. The greater the difference between the spectral distribution of the light source and the spectral distribution of sunlight, the lower the color rendering index. The color rendering index of a common electric light source is as shown in 1.
According to the "Design Specification for TV Studio Lighting System", color TV lighting requires that the color rendering index of the light source be not less than 85. If the color rendering index of the light source is too low, the color quality of the color image will be greatly affected. That is to say, a light source having a color rendering index lower than 85 cannot be used in a television studio. In the past, in order to save investment, individual TV stations did not use high-color three-primary fluorescent lamps in the news studio, but used ordinary fluorescent lamps.
Ordinary fluorescent lamps have a color rendering index of about 70, which is seriously lacking in red light. Therefore, we see that the broadcaster's face is heavily bluish in the TV picture, which is not allowed.
The color temperature of the color temperature source of the light source is an amount representing the color of the light source. In the case of a black body (charcoal is close to the black body), there is a unique correspondence between color and temperature. That is to say, the black body has only one color at a certain temperature. On the contrary, the black body of a certain color only corresponds to A temperature. A heat radiation source, if its color is the same as the color of the black body at a certain temperature, the temperature of the black body is referred to as the color temperature of the light source, referred to as the color temperature. Our commonly used incandescent and tungsten halogen lamps are based on tungsten filament thermal radiation, and their spectral distribution is continuous and smooth. In this sense, only the heat radiation source has a true color temperature.
The luminescence spectrum of a gas discharge lamp source is not smooth, but comb-like, and its color cannot be expressed by the amount of "color temperature". However, its spectral distribution is close to that of the black body, and it does not cause large errors in use. Therefore, when the color of the gas discharge lamp is close to the color of the black body at a certain temperature, the temperature of the black body is referred to as the relevant color temperature of the gas discharge lamp, referred to as "correlated color temperature". In the industry, when introducing a gas discharge light source, it is often referred to as the "color temperature" of the light source, which actually refers to the correlated color temperature. The "correlated color temperature" of the gas discharge lamp described herein is also referred to as "color temperature".
The color temperature required by common cameras has two files, one is 3200K, the other is 5600K. The color temperature in the general studio is 3200K, and the color temperature is 5600K for outdoor football games or other activities. When selecting a light source, the conditions of use of the camera should be met. Traditional studios use the 3200K light source without exception.
In the studio under construction, there is an open studio with one or two walls or three walls of glass. There are two main reasons for this design. First, the use of the news studio is long. The use of daylighting can save a lot of energy. Second, the studio window is often streetscape, and the streetscape in the camera is closer to life. In such a studio, the light source should select a high color temperature light source that is consistent with the daylight color temperature. Usually, the color temperature of the selected light source is about 5600K. At the same time, when considering cloudy weather, the color temperature of outdoor light will be higher than 5600K. Therefore, the studio should also have a certain number of color temperature filter filters to reduce the outdoor light of high color temperature to about 5600K, which is ideal. Image effect. There is also an open studio with glazing, opaque curtains in the window, and lamps with low color temperature sources, namely two color temperatures and two lamps. This is more flexible, but the investment is larger.
In the past, large variety studios used low color temperature light sources. In the past two years, TV studios illuminated with high color temperature light sources have gradually increased. Because the cameras are sensitive to blue, the spectral distribution of high color temperature light sources is basically equal energy distribution, and the blue color is relatively more than the low color temperature light sources. Therefore, the TV image is relatively "transparent". The so-called "transparent" means that people feel that the image has high color saturation, clear image and large depth of field. Recently, outdoor large-scale evening parties have used high-color temperature light sources, and high-temperature light sources have been used for the Spring Festival evenings, and even large studios with high color temperature light sources have been built.
Whether the dimming light source of the light source is easy to dim is also one of the factors for selecting the light source. The reason why the tungsten halogen lamp is used in the studio for a long time is not only good color rendering, but also because it is easy to dim, as long as the voltage across the light source is adjusted, the brightness of the light source can be adjusted, and the equipment is simple and the investment is small. The high-color three-primary fluorescent lamps widely used in the studio now adjust the brightness of the light source by frequency modulation, and the relative investment is relatively large. At present, most gas discharge lamps cannot be dimmed. In this case, the light output of the lamp is adjusted by adjusting the diaphragm on the lamp to achieve the purpose of adjusting the illumination intensity of the field.
The efficacy of the light source of the light source is an important indicator. It is expressed in lumens per unit of active power output. For a tungsten halogen lamp, the light source is equal to the luminous flux emitted by the source divided by the active power consumed by the source. For example, the luminous flux of a 2000W tungsten halogen lamp is 48000 lm, and the luminous efficiency is 48000 ÷ 2000 = 24 lm / W. For a gas discharge lamp, the electric power consumed by the light source should include the active power consumed by the light source itself, and should also include the consumption of the ballast. Active power.
For example, the 36W high color rendering trichromatic fluorescent lamp output has a luminous flux of 3350 lm. If the active loss of the ballast is not considered, the luminous efficiency is 93 lm/W.
If you consider the active power loss of the ballast, the light efficiency will be lower. Ballasts of various brands have different active power losses, and thus the light source efficacy is also different. For example, the ballast's active power loss of a certain brand is 4.5W, the total active power loss of the light source is 40.5W, and its luminous efficiency is 3350÷40.5=83lm/W. Thus, the light of the high color rendering trichromatic fluorescent lamp can be seen. The effect is 3.5 times that of halogen halogen. If a news studio uses a tungsten halogen lamp of 7.5 kW, if it is replaced by a high-color three-color fluorescent lamp, only 2 kW can achieve the original illuminance. It can be seen that the energy-saving effect of the high-efficiency light source is very obvious. Not only that, but because of the large reduction in power consumption, the power consumption of air conditioners has been greatly reduced. Therefore, the use of high-efficiency light sources in the studio is of great significance.
idc cable connector,10 pin idc cable,ribbon cable assembly,ribbon cable alternative
Dongguan Bofan technology Co., LTD , https://www.ufriendcc.com