What is the human perspective?

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The maximum horizontal visual angle of a person can reach 156 degrees with one eye and 188 degrees with both eyes. The overlapping visual field of human eyes is 124 degrees, and the comfortable visual field of one eye is 60 degrees.

1. What the human eye actually sees is not only a plane with overlapping perspectives, but a circular plane with 188 degrees above the fisheye lens, similar to the recently popular circular movie screen.

2. The overlapping visual field of human eyes is 124 degrees. That is to say, within the range of human eyes, only objects within the visual angle of 124 degrees have stereoscopic effect. In other words, only when the cross section of the object observed in the overlapping field of vision of 124 degrees exceeds 180 degrees can the stereoscopic effect be formed.

3. The monocular comfortable field of vision is 60 degrees. It is said that only this object within 60 degrees of one eye can be seen clearly and focused by the human eye. The peripheral part beyond the horizontal field of view angle of 30 degrees is called induced field of view, commonly known as the eye's residual light, which is actually the insensitive range of the human eye, that is, it can't be seen clearly.

Of course, what we need to study is the stereoscopic vision presented by the eyes. The above part only states the basic knowledge, and the following part begins to discuss the perspective of stereoscopic vision.

Binocular perspective view

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1.∠xyz is actually the position blocked by the nose. The whole white range in Figure 2 is actually a blind spot for human eyes, except that you can see your nose and eyes.

2. In fact, only what you see in the range of ∠cyg has a three-dimensional sense.

3. A person's monocular comfortable field of vision is only 60 degrees, that is, 60 degrees is the best object to watch and take photos; The maximum range of stereo photography is monocular 124 degrees (156-90-4)×2, which is the line-of-sight level of two lenses, and the angles from double lines of sight to the inside of eyes are ∠ixg and ∠czj.

4. Let's talk about comfortable 60-degree stereoscopic imaging. As you can see, the line bf is the synthetic stereo photo we shot with a 60-degree lens. Where bk and lf are non-overlapping two-dimensional parts and kl is overlapping three-dimensional parts. I believe that most friends will find this problem when shooting stereoscopic photography and stereoscopic video.

Visual angle limit

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The visual angle limit of human eyes is about 150 degrees in the vertical direction and about 230 degrees in the horizontal direction. If all the screens are within this viewing angle, it will give us an immersive feeling. But this angle is too big. Usually, only a movie with a circular screen can achieve this effect. In fact, human vision is a sensitive area at 10 degrees, which can correctly identify information, and it is sensitive to dynamic things at 20 ~ 30 degrees. When the vertical viewing angle of the image is 20 degrees and the horizontal viewing angle is 36 degrees, it will have a very good visual presence and will not be tired because of frequent eye movements.