51 utenti della rete avevano questa curiosità: Spiegami: Why does taking a photo of a screen cause lines to appear? Why do these lines change as I zoom in on the picture?
Spiegami: Why does taking a photo of a screen cause lines to appear? Why do these lines change as I zoom in on the picture?
Ed ecco le risposte:
They’re called Moiré patterns http://en.wikipedia.org/wiki/Moir%C3%A9_pattern
It’s caued by the interferance pattern between the pixel grid in your camera’s sensor, the pixel grid on the screen your photographing and the pixel grid on your phone’s screen (which is why they change when you zoom)
If you take a picture of window screen or other regular square pattern you can see the same thing. You can even see them in the real world by looking through two layers of wire screens (an apropriate distance appart)
(The reason they’re curved is because different parts of the monitor are different distances from the camera sensor so the interferance frequency changes .)
Well, I was going to say that the screens refresh rate (usually 60 cycles per second) differs from your shutter speed (for video) and a still image simply catches the screen refresh mid cycle.
If you need to film an image for video, set the shutter speed to 60fps and it should look seamless.