When we use mobile phones to shoot computer and TV screens, we always find some "water ripples" that affect the picture. So how do these "water ripples" come into being? How can we eliminate it?
In fact, these "water ripples" are generated because the screen refresh rate is lower than the shutter speed of the mobile phone. The refresh rate is often referred to as the Hertz (hz) of the screen. Our usual refresh rate of the old TV is 50 hz, and the newer one is 60 hz. Now most of the LCD monitors we use are also 60 hz by default.
Because the screen is not always glowing, but will refresh every other time. For example, the 50 hz represents 50 refreshes per second. The human eye is completely unaware of any flicker on the screen. When a mobile phone shoots a screen, most of them will also have a faster shutter speed. When the shutter speed is faster than the refresh rate, we can catch the screen refresh process invisible to the naked eye, which will produce "water ripple".
To eliminate water ripples, it is actually very simple to slow down the shutter speed. If you use an SLR or an M-level digital camera, you can control the water ripple by adjusting the shutter speed. However, most mobile phones do not support shutter speed adjustment. So it is really difficult for mobile phones to take completely water free pictures when shooting the screen. Some mobile phones now have an option to "reduce flicker", in which you can adjust 50hz, 60hz or automatic settings. This setting is specially added for such situations, but the effect is not obvious. So when shooting the screen, you have to bear the water ripple, or pray that the "reduce flicker" in your mobile phone can play a role.
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