LED advertising screen phenomenon of water ripple

 In daily life, when we see beautiful pictures on TV, often pick up the phone to record down, and at this point, the photo flash tend to appear on the water ripples and scan lines. In can also bring gorgeous pictures of LED advertising screen before the photos, also can appear ripples and scan lines, there are some customers doubt about the quality of the LED advertising screen. Below small make up detailed analysis to the customer in the heart of doubt, the picture of water ripple and scan lines are not LED display board caused by quality problems, but because when you take a photo in mobile phone, camera Angle and focal length.

First. Concept of water ripple
"Water ripple" also called "Moore lines," Moore grain is a kind of expression of the principle of beat. Mathematically speaking, the superposition of the continuous sine wave frequency close to two synthetic signal amplitude will change according to the difference between the two frequencies.
Second: appearance of MOORE LINES
Two slightly different spatial frequency stripe, they left black line position, due to different interval with, to the right gradually refreshed line can't overlap.The results of the two overlapping stripes, on the left because of the black line overlap, so I can see the white line.And right dislocation, white line on the black line, overlapping the outcome become all black.Have the change of the white line and all black, comprise the mole.
Third: appearance of led advertising screen moore lines
If LED electronic signs pixel distribution density between the camera can distinguish between the case, then will can decipher the part identification results, but because of LED advertising screen can't identify the ash terrace zone, a combination of both will form the regularity of the grain, response is periodic ripples on the vision.
Forth: how to delete Moore Lines
1, change the camera position. By around or move up and down, can reduce the ripple Moore.2, change focus. Hd LED large screen due to the focus of the image clearly and height details may cause Moore corrugated production, slightly adjust the camera focus to change resolution, and thus help eliminate Moore.3, change the camera Angle. Moore corrugated, due to camera fixed Angle will be slightly adjust the Angle of the camera, is a good way to slow Moore lines.4, use mirror filter installed directly in front of the camera lens, make its exposure conditions satisfy the spatial frequency, high spatial frequency part thoroughly filtered image, opportunities for decreasing the occurrence of Moore's grain, but it will also be synchronous reduce the sharpness of the image.5, change the lens focal length. Can use different lenses or adjust the focal length, to change or remove Moore.