What are the similarities and differences between human eyes and cameras?

Aperture is used to control the amount of light entering the camera, that is, to control the exposure. For example, the smaller the number of f2.8f3.8, the greater the amount of light entering; The iris also controls the pupil and the amount of light. We can't look at the sun directly with our eyes, and neither can our cameras.

A lot of light entering every minute will turn the camera into a dead machine, because the huge light will directly shine on the retina and burn your retina, and the camera will also burn the CCD.

So in the strong light, we always shrink our eyes involuntarily. When the camera is turned on automatically, you will hear Kaka's voice from time to time, which is the sound that it automatically adjusts the aperture.

2. shutter vs eyelid:

Shutter is to control the residence time of light entering the sensor, and the unit is time, which is generally expressed by1/201/5001/6000, and some can even reach110000/kloc-.

On the contrary, the slower the speed, the longer the light stays on the sensor, and the more tracks are displayed, the more blurred it is, which is very suitable for shooting traffic (streamer) and waterfalls at night.

Eyelids are the same. Try shaking your head or looking at something moving fast. Close your eyes for a second and think about what you see. Nonsense, of course you didn't see anything. Everyone's eyes have a limited ability to catch moving objects.

3.ISO (sensitivity) and retinal vision:

ISO is more sensitive, and the numbers of100,500 and 1600 indicate that the greater the sensitivity and adjustability, the stronger the sensitivity to light at night, because it is not light, and it is nonsense at night. However, although you look obvious at night, the situation is still unclear.

Compared with the eyes, it is the acuity of the retina. Retinal pyramidal cells are most sensitive during the day, and rod cells work at night. But when we look at the stars at night, the more you notice a star, the less you can see it. Only by looking around can you see the stars you want to see clearly.

This is because when we pay attention to an object at night, we will use the central depression (a pit) to detect light. However, there are only pyramidal cells in the central fossa, which are not as sensitive as rod cells at night, so the more you pay attention to the darker the light. But the camera doesn't have this pit, so the sensitivity is getting higher and higher.

Extended data:

This technique comes from the fact that photography always uses the ISO aperture shutter (that is, in the M position).

Of course, you can also use various automatic modes, so this is also the difference between a fool camera and a SLR camera, because the extreme values of these parameters of a fool camera are very bad and cannot be adjusted.

But it is usually the brain, not the camera, that determines the quality of photos. Just as everyone has eyes, beauty is hard to find.

A camera (non-zoom lens) produces a clear image by adjusting the distance between the lens and the film, and produces an object by changing the distance between the object and the image.

The eye uses muscles to change the shape of the lens, that is, the focal length, to obtain a clear image.