Application of LED lamps in the field of film and television lighting

With the rapid development of semiconductor technology, LED lamps and lanterns have set off a revolutionary wave in the lighting industry with their technical advantages of high light efficiency, low energy consumption, long life and multi-function. LED has been widely recognized and used in the field of public lighting, and has also attracted active attention and response in the field of film and television lighting. Comparing and analyzing the performance characteristics of LED lamps and traditional film and television lamps, understanding and exploring the application rules of LED lamps and lanterns in the field of film and television lighting has positive significance for us to do film and television lighting work well. Combining with the practical experience of Zhejiang Radio and Television Group in the application of LED lamps in recent years, we propose the following characteristics analysis of the application of LED lamps in the field of film and television lighting.

For luminaires of film and television lighting, illuminance is the characteristic we need to consider. Compared to traditional tungsten spotlights, insufficient illumination has always been a problem with LED lights *. Low illuminance of lamps and short range of action are also the main reasons why LED lamps were not recognized by the industry in the past. However, with the continuous improvement of the luminous efficiency of LED components, the practical illumination of LED lamps has been catching up with traditional lamps at an alarming rate. In 2005, we used 90W LED spotlights for the second time, and the illuminance at a distance of 2 meters was not as good as the 500W lamps with the lowest power in the spotlight series. But in 2007, we chose astigmatism LED color-changing lamps, although only 136W of total power, but in terms of white light and various colors of illuminance are not lost to the commonly used 1000W ground row lights. In 2009, the concert hall after the TV broadcasting transformation of Zhejiang Broadcasting and Television Group chose 450W LED lamps combined with red, green and blue lamp beads, which are stronger than the 2000W tungsten filament spotlight and 1200W metal tungsten halide in the combination of white light and color light function. Computer stained lamp with lamp light source. In 2010, 100W and 200W white light LED lamps were used in the 180 square meter duplex news studio of Zhejiang Radio and Television Group, which is equivalent to the traditional 1000W and 2000W tungsten spotlights in white light.

Once the technical bottleneck of high power and high brightness is broken, the advantages of LED lamps in color light and energy saving can be fully promoted.

As early as the LED technology just involved in the field of film and television lighting, the delicate and high-quality color light function of LED lamps was shocking. Of course, the price was also shockingly high at that time, but because of the low power and low illumination, it could not match the traditional lamps. Only failed to attract enough attention. At this stage, when the illumination is not a problem, the superiority of LED lamps in color conversion is unmatched by traditional lamps and has an overwhelming advantage.

For traditional lamps with a single color light source mainly white light, whether it is a tungsten light source spotlight, astigmatism light, beam light, or a metal halide light source computer light, to produce colored light, it is used in the output light channel of the lamp Add color paper and color film. The light transmittance of various colored papers and color chips is high or low, but in principle it is a subtractive color superposition. In order to produce non-light source color light, it is necessary to absorb some spectral components and reduce the effective luminous flux. LED lamps used for color change usually use a reasonable arrangement of multiple red, green and blue (or more) lamp beads, and synthesize different effects of color light by turning on different primary color lamp beads. Because the color light generation of LED lamps is a kind of additive color mixing, the luminous flux generated by all lamp beads is effectively converted into actual light effect, and there is no invalid absorption and loss after the excellent light effect.

Compared with traditional lamps, LED not only has a significant improvement in the actual effect of luminous flux of colored light, but also has a richer variety of colored light, and more delicate colors. In addition to adding high-end computer lights with CMY color mixing function, other traditional lamps, whether they are equipped with a color changer in front of the lamp or a glass color wheel in front of the light source, a lamp can generally produce only 7 to 11 kinds of colored light. The LED lamps combined with the three primary colors of red, green and blue can be produced linearly under the electronic control of each lamp bead *, and different types of pure color light are mixed by the additive method of different brightness.

For large-scale use of high-power lamps and lanterns for film and television lighting, fire safety is always a matter of vigilance. High-power tungsten filament lamps and metal halide lamps produce a large amount of thermal effects during operation, which will put the lamp body in a high temperature state, and must maintain a sufficient safe distance between the lamp and flammable objects during operation. Long-term high-power consumption will also cause aging and heating phenomena on the power lines of the system. The high-temperature lamp body and the hot cable are the main safety hazards of film and television lighting under traditional light sources.

The LED light source has very good photoelectric conversion efficiency, almost all of the electrical energy consumed is converted into light energy, the thermal effect is very low, and the problem of high temperature of the lamp body is solved from the source. The low power brought by high light efficiency also makes the power supply line low load, of course, the line safety is good. After replacing traditional floor lamps, beam lamps, and spotlights with LED lamps, we are much more at ease when illuminating flammable materials such as cloth and wood. Of course, LED lamps do not have any heat during operation. The control circuit will also generate a certain amount of heat. If the lamp is lit for a long time, the lamp body will still have a certain temperature. The vigilance of the safety lamp can’t be relaxed at all times.

In addition, the current LED lamp body manufacturing process is generally superior to traditional spotlights. The closed structure of electronic products makes the protection level of LED lamps reach IP65. Compared with traditional spotlights, the safety of LED lamps has been greatly improved.