Date：2015/11/26 source：ENTERTAINMENT TECHNOLOGY

LED large screen impact In recent years, with the stage of scientific and technological progress and the means of increasingly rich means, in many large variety show, the traditional design of the dance scene has become increasingly fade out, replaced by a strong expression of the LED color Screen screen and full LED large screen (hereinafter referred to as LED large screen) use. Because of its large scene with the music song and dance, to render the joy of joy, warm, passion of the scene effect, the stage actor and performers and viewers view the visual integration, so that the audience as immersive; The program content is flexible, so more and more by the TV directors favor. Nearly two years of CCTV (CCTV) Spring Festival Gala, the use of the whole stage LED large screen (see Figure 1), expressive and compelling, so that the stage on the point, line, face, etc. are to show the art of choreography Components, with advanced technology (Augmented Reality, referred to as AR), for the audience to create a true and fantastic artistic atmosphere, has achieved great success. But at the same time, we also see that the large-scale application of LED large screen for the art of lighting also has some adverse effects: (1) its high brightness (although can be adjusted), color temperature is high, especially the stage light (2) its high brightness, rich color, making the stage of the scene, so that the appearance of the face is not enough, (3) due to the ground, including almost all corners are covered with LED large screen, like a box around the box, although the picture is beautiful, but it is beautiful, but the screen is too beautiful, Easy to give the audience a "full" and "blocking" feeling. At this point, the stage lighting is often purely into the use of light, even if the use of hundreds of computer lights, but also can not play the desired artistic effect, very sorry. So, how to deal with the stage background and the use of light off So that the two complement each other, complement each other, is a need to seriously explore the problem 。2.1 to change the lighting design concept In the large-screen LED and other large-scale light-emitting elements before the appearance of the scene on the bright and dark, the overall picture of the light control by the lighting designers. When a large number of self-luminous elements into the composition of the camera, the TV lighting design concept gradually from the dark environment of the lighting design to the bright scene of the light balance, that is, balance the light source and large screen illumination and color temperature, balance the main characters With luminous background brightness and color. Traditional TV lighting production, reflecting the contrast of the brightness of the object, the camera will be the brightness of the object to be photographed; illumination and contrast to meet the requirements, the screen level, color, clarity can achieve satisfactory results. And LED large screen as the main background applied to the TV variety show, the lighting division in the design, it must be taken into its own luminous characteristics, as a large LED lighting, because of its video content display different, its light and shade , The color also has different changes, does not affect the effect of dance and ensure the basis of illumination under the premise of constantly adjust the lighting layout, not only to rational use of light brightness, light ratio, control the actors and figures, the level of contrast, Actors and luminous LED large screen brightness balance, master the stage of the overall color changes; so that the night light color tone and the content of harmony and unity, so that LED large screen completely integrated into the TV stage, and television lights seamless, so that the TV screen to be true Natural color reproduction. 2.2 light ratio, aperture, color temperature, video and other adjustments to the application of LED large screen for the stage basic illumination, character modeling level and color reproduction have an impact. LED large screen for TV variety show, its own luminous brightness to a certain extent, the impact of the effect of television recording: in the play when the illumination is certain, if the big screen brightness is too high, the actors face will darken; large screen brightness Too low, will make the audience can not see the content. The lighting design requires a balance between the subject and the large screen of the light. Because the presentation of the television picture and the clarity of the image does not depend on how bright the whole picture is and how much illumination is used, the key is to use the appropriate shading contrast and the corresponding light properties. Good TV picture lighting is not necessarily high, but rather the proportion of appropriate light. We have such a experience: in the recording of television programs, the director often feel the screen "not bright", asked to improve the light of the illumination, but often put up the brightness, behind the background of the big screen brightness is also high, in the close-up lens The big screen will be brighter than the face, causing the face to be dull. The level of the characters did not highlight the level, can not improve the quality of the screen. For the use of LED large screen generated by the above problems, I believe that the following aspects can be resolved from the following aspects: (1) dimming ratio can increase the stage performance area by the brightness or reduce the brightness of large screen method to reduce the face and background Light ratio. If you increase the brightness of the stage performance area, on the one hand is bound to increase the number of lamps and power supply equipment capacity, bringing heat and a series of problems; and in general, play the degree of illumination can reach 1 000 lx, has been able to meet the high-definition camera shooting needs The So most of us use the method to reduce the brightness of large screen. To the camera from the big screen about 15 m ~ 18 m, LED large screen self-test color bar as the standard, according to the LED large screen size, greater than 20 m2 brightness adjusted to about 25% of the maximum, less than 10 m2 brightness adjusted to 35% Is appropriate However, if the actors are close to the LED large screen, you need to shoot for a long time, with the LED large screen content and color changes, the camera shooting close-up picture of the face of the dark, the background showing white mosaic situation; You can localize the face of the cloth, and then through the aperture adjustment, to balance the character and the background of the brightness of the foil. (2) constant aperture due to the continuous improvement of camera sensitivity, coupled with a lot of programs have been used in high-definition shooting, studio recording program, will use a lower illumination, usually controlled at 800 lx-1 000 lx or so, aperture F4 ~ F5. 6 between. It is generally believed that F5.6 is a better aperture value. The general experience is: in the actual recording rehearsal period, the lighting division and video technician will first determine the basis of a program based on the aperture range, this range must always ensure that the camera in the best working condition, that is, between F4 ~ F5.6 The In this aperture range to complete the basic lighting needs of the camera layout, to determine the brightness of the LED large screen, and then do the lights, the effect of the art of embellishment. In this way, each program of video technology staff can be based on this small adjustment aperture, to ensure that the visual effects and technical quality requirements. (3) Balancing the color temperature camera is sensitive to the color temperature of the light source. If the color temperature of the light source is lower than the camera requirements, the picture will be reddish; otherwise, the picture is bluish. Variety show often use a variety of stage lighting, in order to ensure that the evening recorded TV color effects, as far as possible so that the color temperature of various lamps consistent. Now popular use of a large number of computer lights do surface light, that is, the use of high color temperature lamps. Because the LED large screen for high color temperature equipment, if the computer lights use 2 800 K ~ 3 200 K or so low color temperature lamps to face exposure based on exposure, shooting out of the LED large screen will appear blue, making color distortion; Such as light adjustment for the high color temperature lamps, and the back of the big screen together, so that the image can be formed to form a consistency. 3 Conclusion Any new technology is a double-edged sword, a reasonable degree to control it, use it, is the key to success. In fact, less use on the stage even without the big screen of the choreography design is not uncommon. For example, 2013 CCTV 15th Youth Singer Grand Prix, high hanging a large LED large screen (see Figure 2), to avoid the LED large screen screen to watch the impact of the audience, the entire stage all over the computer lights, highlighting the Players, all kinds of light effect beam set off the stage was beautiful. Another example, Jiangsu TV "all-around Star Wars", chu-chan design simple and low-key, only in the audience above the high hanging two large LED screen, the main stage is no big LED screen, light beam structure alone a good perspective Sense and sense of space, beautiful and moving (see Figure 3). For example, in Copenhagen, Denmark held in 2014, the European singing contest all use projection equipment, not using the traditional LED display so we do not have to blindly pursue large-scale use of LED large screen, a party, you can use LED lights, can also be used Computer lights, or a combination of the two, the LED screen for segmentation, free combination, computer light beam inlaid them, sway the stage. In short, the combination is used, do not give up, all the means of expression are based on the program content and the main object as the basis, so that LED large screen and lighting design, video technology complement each other, better integration with the program content for the audience to provide high quality Of the TV screen.

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