Believe that many people have this kind of experience. When shooting a full-color LED display screen, there appears some irregular water ripples. Physically these water ripples are called "moiré".
The main influence of the moiré phenomenon lies in TV camera, and the most widely used one is the fine-pitch LED display. If the existing LED display has unbalanced illumination between pixels, the imaging effect abnormal, or the glare is closely watched, there will be moiré, which will affect the promotion and use of the LED display in the studio. Mini led display application in TV Station is below:
When two patterns with spatial frequencies overlap, another new pattern is usually produced. This new pattern is often called amoiré. As shown below:
Moiré is a manifestation of the beat principle. The beat principle is widely used in broadcast television and communication for frequency conversion, modulation, and so on.
How to improve or even eliminate this moiré phenomenon, the solutions are as follows:
1. Change the camera angle. The angle that the camera captures an object will cause a moiré. So slightly changes the angle of the camera, or rotates the camera, the moiré can be eliminated.
2. Change the camera position. In addition, the moiré can be reduced by changing the angular relationship by moving left and right or up and down.
3. Change the focus. Too sharp focus and high detail can lead to moiré, and a slight change in focus can change the sharpness, which in turn helps eliminate moiré.
4. Change the lens focal length. Different lens or focal length settings can be used to change or eliminate moiré.
5. Use the pre-mirror filter directly on the front of the CCD to make the exposure conditions meet the spatial frequency, thoroughly filter the high spatial frequency part of the image, and reduce the chance of moiré, but this will also reduce the sharpness of the image.
6. The production of high-quality LED display (such as black LED lights, good consistency) LED light brightness and color, good uniformity).
Hope the above information will help everyone know better about moiré, and find solutions when this happens.