ELi5: When taking a photo of a screen, why are the images are so distorted?
In: Technology
If you are taking a camera photo of your TV or computer screen you can get what I will call “The Strobe Light Effect” it is related to the effect of videos showing car wheels looking like they are rotating backwards. The TV screen is being replaced constantly moving from top to bottom. You don’t see it with your eyes because of something called persistence of vision, but your camera takes a very quick picture that catches the screen being changed halfway through.
I think what you’re looking at is the [moire effect](https://en.wikipedia.org/wiki/Moir%C3%A9_pattern). Intersecting grids at slight angles to each other can cause weird artifacts. In this case, the first grid is the pixels on your screen, and the second grid is the pixels being produced by your camera sensor.
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