Excuse me, how to distinguish between virtual image and real image?

Virtual image is a physical vocabulary. If the beam diverges, the intersection of its reflection line and its backward extension line is called the virtual image point of the object point, and its collection point is called the "virtual image" of the object. The virtual image is beyond the reach of actual light, so the light curtain is unacceptable.

Real image:

Real images are images that can be presented on a light screen. It is formed by the convergence of actual light, and the real image can only be generated when the light source is not in the main focus. An image in which light is reflected by concave mirror or refracted by a convex lens and fused together. It can be displayed on the screen, or it can make the photographic negative sensitive, and it must be used for photography or film projection. Only when the light source is out of the main focus can a real image be generated. Real images are upside down.

Similarities and differences between virtual image and real image

In fact, everyone has no doubt about the definition of real image and virtual image, but they are full of doubts about the essence of virtual image: the biggest question is, since virtual image is not real and it is not on the screen, why can we still see it, or even see the "extension line" that does not exist and does not shine?

In a word, what does the "virtual" of virtual image mean?

Some teachers will say that it is the human brain's processing of the human eye that makes us see things that we didn't have (that's how ghosts appear), but when we think about it carefully, we will find that without the brain, only the "eyes", the camera can shoot the same things as the human eye. So, don't say that we didn't see anything, we must have seen it, and when we saw it, there must be really light entering the human eye or the lens of the camera! Even if the human eye is biased, will the camera be biased?

But the virtual image does not exist and there is no light (there is no image on the screen). How can I see it? In other words, the biggest paradox is: how do we see things that don't shine?

In fact, the answer is that many people's descriptions of virtual images are wrong. Virtual images don't exist and we can't see them. In fact, we see the actual light from the real image, but:

1) For a flat mirror, it is reflective, and the image and the object are on the opposite side;

2) For the lens (including water), it is refractive, as if everything is on the same side (such as fish or chopsticks in the water, or what a magnifying glass sees);

However, when we saw it, we thought we were taking pictures with the camera in the mirror, and the fish in the water was where we saw it. Of course, the deity's person or fish is in other positions because of reflection or refraction. So "the position you see" has no deity. We call the "image" in this position a virtual image.

It can be seen that the virtual image does not emit light, the virtual image is not an image, and the virtual image is just a "virtual" position. What we see is the real image, but this real image has moved to the "virtual" position because of reflection or refraction. Therefore, strictly speaking, the essence of virtual image is not image, but virtual position.

What we see with our eyes but can't be seen by the camera is called "illusion", which is common in schizophrenia.

Light, whether in the form of particles or waves, is essentially a manifestation of material movement, and will not be reflected by a plane mirror, but by any object. You can see an object because photons from the sun enter your eyes through the object. What you actually see is not the object itself, but is analyzed by the visual system and transmitted to the brain. Due to the experience of using both hands and eyes, the brain perceives the image composed of colors as a three-dimensional image close to reality, the most typical of which are retinal inverted image and orthographic projection. A flat mirror is equivalent to a TV screen. The only difference is that the light of the TV screen comes from the LED in the screen, while the light of the flat mirror comes from the reflection of other objects. But in any case, the final position of photons is concentrated on the surface of the plane mirror, and people's eyes will not rotate, so the brain intuitively thinks that photons are emitted by the plane mirror, thus thinking that the image comes from the plane mirror, so the virtual image is actually photons emitted by the plane mirror, which is the secondary reflection of sunlight. Therefore,

-small dividing line.

A topic found on the Internet:

In my opinion:

(a) A virtual image is not an illusion, but as long as it can be seen, there must be light entering the human eye, but there is no light in the virtual image, so A is half right and half wrong;

(b) People can only see the real image, but the real image has shifted or changed, and the virtual image does not actually exist, so B is wrong;

(C)C is correct, the virtual image is not an image, it does not emit light, it is just a position where the real image changes;

(D)D error, the convex lens can also present a virtual image.

Please note that in the plane mirror imaging of Baidu Encyclopedia, the plane mirror imaging is described as follows: "We saw our virtual image in the plane". According to my analysis above, this guy is talking nonsense. My summary of flat mirror imaging is: "We see the real images of light reflected from the surface of the flat mirror, but we think that the light of these real images is only emitted from the virtual position (virtual image)."

I think I have made it clear enough, and I hope everyone can understand. Of course, this is just my personal understanding. What I said may be wrong. Please correct me.