Can moire fringes explain the quality of the screen?

-Moire, a photographer's nightmare, whether you are a white photographer or an old photographer.

Presumably, when many friends shoot screen objects, such as TV, monitor, mobile phone screen, tablet computer screen and so on. They will have the trouble of looking at a very clear screen, but after shooting with a camera, circles of ripples appear in the photo, which not only affects the color and clarity of the screen, but also looks unsightly.

This kind of ripple in the process of shooting is scientifically called moire effect. Many readers may feel that "moire" seems to be a French word when they see moire. In fact, it was the ancient French name for the corrugated striped silk imported from China, which was later "expropriated" by moire characters.

With a rigorous attitude, we should not only "know why" but also "why". So how did the moire fringe come into being? What is its principle? Look at the depth revealed by ZOL:

Moire fringe is actually a phenomenon produced by the superposition principle of physics, and it is actually a wave interference phenomenon between different objects. We also learned in math class that waveforms are superimposed. Generally speaking, for example, when the peaks of two sine waves are superimposed, the waveform will change.

Schematic diagram of moire fringe generation principle

When we lift the camera to take pictures, the photosensitive elements inside the camera will release high-frequency electromagnetic waves. Photographic objects, such as liquid crystal displays, will also release certain electromagnetic interference. Suppose that the photosensitive element of the camera emits one waveform and the LCD emits another waveform, then when the two electromagnetic waves intersect, the waveforms overlap and interfere with each other, changing the original waveform, forming a new waveform, and moire fringes appear.

Screenshots are essential, but moire fringes are everywhere.

Screen photography (short for screen photography) is essential in many occasions. For example, when we use a computer, we need to grab the whole screen, but it is not convenient to take screenshots at this time, so we have to take screenshots. For example, when we compare the screens of two different monitors, TV or mobile phone, we need to distinguish the advantages and disadvantages of screen expression for others through screen capture.

This damn ripple!

Screen capture is inevitable, and we can't stop the emergence of electromagnetic waves, which seems to be a very contradictory and tangled thing. At this time, we sighed: What should we do?

Moire lines will also appear on the lines of clothes.

This situation does not only happen on the shooting screen, for example, when shooting clothes with very dense fibers, the imaging element pattern of the camera may overlap with the clothing grain image, and the moire phenomenon appears again.

After reading the above introduction, do you think moire is like a scourge, and you can't escape it? Of course, we can't take this pessimistic attitude, because the problem is just for us to solve. Theoretically, we already know the general principle of moire fringe, which plays a vital role in cracking moire fringe.