What if the camera shakes the computer?

1. Why does the camera shake when shooting the computer screen?

The working principle of signal processing is different, mainly the frequency is different!

In order to be suitable for human observation, the refresh frequency of computer monitors is generally 60- 100Hz or even higher. The higher the frequency, people will not feel shaking (ripple flashing) when watching the computer. If the computer refresh frequency is a little low, it is obvious that the screen is flickering unsteadily! The refresh frequency will be higher at this time. The refresh rate is a very important parameter of the monitor! ! The higher the refresh frequency, the better the effect! Personal use of the computer, it is not recommended to set it too high, which will increase the "workload" of the monitor (personal language)!

Cameras are usually compatible with televisions. The frequency of the TV set (field frequency: scanning up and down) is 50Hz. Simple understanding: there are 50 pictures per second, but there are actually 25 pictures, and each picture is displayed twice. The movie film is 24 pictures, which are flashed twice a second. So comparing the working principle and signal quality, the computer is the most stable, followed by TV, and finally the movie! I majored in electronic communication in my early years, and the above is just my superficial understanding!

Therefore, two devices with different scanning frequencies (up and down) will obviously roll with the naked eye because of the low frequency (the jitter you said), and it will roll up and down, not left and right (TV line scanning: left and right, the frequency is higher, which is good for the naked eye)!

2. Why does the camera screen keep flashing and jumping when shooting a computer screen with a camera?

Your computer monitor is CRT, which is CRT.

The imaging principle of CRT is that rows of electron beams scan the fluorescent screen to produce images. The refresh rate of a computer is generally 60- 100Hz, which means that the computer screen flashes 60- 100 times per second, although it does not flash in our eyes. In detail, it is a top-down refresh process of 60- 100 times per second.

All the monitors you see on TV are taken by cameras. When shooting, most cameras record at a speed of 24 frames per second, that is, moving objects. In fact, the camera breaks down his action into 24 still pictures per second, each of which is only one hundredth or one thousandth of the action time. This is the problem.

The frequencies of cameras and monitors are different. Monitor images that can't be glinted by naked eyes flicker when the camera is shooting at high speed (recording a static image every hundredth of a second to thousandth of a second), and each flicker is different. Then, if you play back such a still image to you at a speed of 24 frames per second, you will naturally feel flickering.

3. What about camera shake when taking pictures?

To prevent shaking when taking pictures, you need to master the essentials of holding the machine. When taking pictures, you should have two hand-held mobile phones, your arms should lean against your body as much as possible, and your body's center of gravity should be stable. You can find a stationary object to lean on for your camera, or find a place to lean on. Hold your breath when you press the shutter, first press the shutter half to focus, and then press the shutter bit by bit when you feel that it will not shake. The photo blur is not necessarily caused by shaking hands, but may also be caused by inaccurate focus. The shutter of a digital camera is basically auto-focusing (except manual focusing) when the shutter is pressed to half, and then pressing it to the bottom to take pictures. If you press it directly to the end, there will be no focusing process and the photo will be blurred.

In addition, when the light is dark, if you don't need a flash to fill the light, you should increase the sensitivity, which can also improve the shutter speed and reduce the jitter coefficient.

If you use a tripod, you should generally use the 2-second * * function to avoid camera shake when you press the shutter.