With the rapid development of LEDs, many stages will also use LED displays during performances. Looking at the stage of TV literary and artistic programs, represented by the CCTV Spring Festival Gala, the most dazzling LED display is undoubtedly the most dazzling. They are based on carefully produced various holographic pictures and dynamic video pictures, which are seamlessly spliced from all directions of the stage to form a near-perfect stage space, supplemented by hundreds of mechanical lifting stages, which visually bring the audience Great impact and enjoyment. Today, YONGS LED introduces the problems caused by the use of large screens on the stage.
Dimming ratio:
The light ratio between the face and the background can be reduced by increasing the brightness of the characters in the stage performance area or reducing the brightness of the large screen. If the brightness of characters in the stage performance area is increased, on the one hand, the number of lamps and the capacity of power supply equipment will be increased, which will bring about a series of problems such as heat dissipation; and generally, if the illuminance in the performance area can reach 1000 lx, it can already meet the shooting needs of high-definition cameras. Therefore, most of us use the method of reducing the brightness of the large screen. The distance from the camera to the large screen is about 15 m ~ 18 m, and the LED large screen self-checking color bar is the standard. According to the size of the LED large screen, the brightness is adjusted to about 25% of the maximum value if it is greater than 20 m2, and the brightness is adjusted to about 35% if it is less than 10 m2. appropriate. However, if the actor is close to the large LED screen and needs to shoot for a long time, with the change of the content and color of the large LED screen, the face of the character in the close-up picture captured by the camera is dark, and the background presents a whitish mosaic situation; at this time, You can locally increase the lighting of the character's face, and then adjust the aperture to balance the brightness of the character and the background.
Fixed aperture:
Due to the continuous improvement of camera sensitivity and the fact that many programs have been shot in high-definition, the studio will use lower illumination when recording programs, usually controlled at about 800 lx-1000 lx, and the aperture is between F4 and F5.6. It is generally believed that F5.6 is the best aperture value. The general experience is: during the actual recording rehearsal, the lighting engineer and video technician will first determine a basic aperture range according to the program form. This range must always be guaranteed to be in the best working state of the camera, that is, between F4 and F5.6. . Complete the basic lighting arrangement required by the camera within this aperture range, determine the brightness of the LED large screen, and then do the artistic embellishment of the computer lights and effect lights. In this way, the video technicians of each program can adjust the aperture in a small range on this basis to ensure the visual effects and technical quality requirements of the picture.
Balanced color temperature:
Variety shows often use a variety of stage lamps. In order to ensure the color effect of the TV recorded at the party, the color temperature of various lamps should be kept as consistent as possible. It is now popular to use a large number of computer lights as surface light, that is, using high color temperature lamps. Because the large LED screen is a high color temperature device, if the computer light uses a low color temperature lamp of about 2800 K ~ 3200 K, and the exposure is based on the face, the large LED screen shot will appear blue, making the color such as face light adjustment For high color temperature lamps, it is consistent with the large screen behind, so that the image can be presented in a consistent manner.
The materials displayed on the large LED screen can be adjusted appropriately:
Because of the use of large-scale LED screens, the resulting brightness will directly affect the stage lighting. At the beginning of the lighting design, we can first consider the LED large screen as a part of the stage lighting. Measure the average brightness of all playing materials, edit and adjust the video screen brightness and color of the playing materials in advance, and adjust the brightness appropriately according to the background materials and lighting design requirements of the actual program without affecting the overall large screen effect. .
