First, the display produces a molar pattern process
Note: If the LED display pixel distribution density is precisely between the CCD can distinguish between the grid, the inevitable digital camera will still be able to read some of the results can be identified, but also with the unrecognizable gray belt, The sum of the two will form a regular pattern, the reaction is in the visual is the periodic ripple.
Second, the "water ripple" scientific name "Moore" (Moiré effect)
With a digital camera to shoot the scene, if there is a dense texture, often appear inexplicable water wave stripe.
Simply put, Moore is the patience of the principle of a performance. Mathematically speaking, the two frequencies close to the equal amplitude sine wave superimposed, the amplitude of the synthesized signal will be in accordance with the difference between the two frequency changes.
Third, the process of Moire pattern
1, the results of these two stripes overlap, the left side due to the black line coincidence, so you can see the white line. And the right gradually dislocation, white line against the black line, overlapping results become black. There are white lines and all black changes, composed of moles.
2, the two spatial frequency slightly different stripes, they left the same black line position, due to the interval is different from the right side of the line can not coincide.
Fourth, the elimination of Moore's method
1, with software processing. Such as Nikon Capture or Photoshop plug-ins, to eliminate any moiré appearances on the final image.
2, change the camera angle. Since the angle of the camera does not cause a molar ripple, the angle of the camera is slightly changed (by rotating the camera) to eliminate or alter any molar ripples present.
3, the use of mirror in front of the filter directly installed in front of the CCD, so that the exposure conditions to meet the spatial frequency, thoroughly filter the high spatial frequency of the image part of the opportunity to reduce the occurrence of moire, but it will simultaneously reduce the sharpness of the image.
4, change the camera position. In addition, by changing the angular relationship by moving left or right or up and down, the molar ripple can be reduced.
5, change the lens length. You can use different lenses or focus lengths to change or eliminate moire ripples.