How to distinguish between real and virtual images, don t say it in writing, I can t understand what

1.An imaginary image is an image that does not exist, for example, when you look in the mirror, you see the image, you can't touch it, it seems to be behind the mirror, when you go to the back to look for it, you touch it, there is none. Why?

Because the virtual image when looking in the mirror is not formed by the intersection of the actual reflected light, but the intersection of the extension line of the actual reflected light, in the mirror, the actual reflected light enters our eyes, and our eyes always think that the light travels in a straight line, that is, they think that the light comes from the place where the virtual image comes, and at this time the eyes are deceived and think that you are in the mirror. Actually, no. But our brains are awake and know that it is fake, not a real object, really in front of a mirror.

And not inside the mirror. Examples include magnified words seen under a magnifying glass, "objects" in the water, images seen in the mirror, mirages, and twinkling stars.

2.The real image is the intersection point of the actual light rays, such as the small hole imaging, there is a vertically placed line light source AB, the light emitted from the above point A obliquely propagates downward along the straight line through the small hole O in front of it, and continues to propagate obliquely downward, at this time, if there is an object blocking it (that is, we often say the light screen), we can see the real image of A A1, or directly look at it with our eyes, and the actual light coming from the straight line from point A will directly enter the eyes. Examples include images on the negatives of small holes, images on the retina of the eye, images on movie screens, images on projector screens, and images on camera negatives.

The simplest criterion is that the actual light is gathered to form a real image.

The virtual light converges to form a virtual image.

Actual light means that the light is actually received on the light screen or is actually received by the eye;

Virtual light is caused by the illusion of the human eye, which always thinks that the light travels in a straight line.

For example, when looking at a mirror, the actual light starts from the object and touches the mirror, is reflected by the mirror, and then turns back to be received by your eyes, which is the actual light path, and this light on your retina becomes a real image; But after this information is processed by your brain, it will make you think that the light of this point is coming from behind the mirror, so the processed image in your brain will be located behind the mirror, but in fact this point does not exist, this image is abstract and virtual. It can be seen from this that the so-called virtual image does not actually exist, it is your brain that thinks it exists.

The fish in the water, if you analyze any point of it, the light at this point first travels in a straight line in the water, and once it encounters the critical interface between water and air, the refraction phenomenon will occur, and this light will deviate from the original straight line and propagate along another straight line, and finally, this light that deviates from the original direction enters your eyes and forms a real image on your retina, but! But! Be careful, your brain will think that the light that enters your eyes is the original light, that is, the light emitted by any point on the fish, there is a misunderstanding in it, in fact, the light path has changed, but the brain thinks that it has not changed, and this light is used to locate the arbitrary point on the fish, so that the positioning point is not the arbitrary point on the original fish, this point is a virtual image!

The real image can be received by the light screen, such as a projector, etc.

Imaginary images cannot be received, such as words under a magnifying glass.

A more intuitive way to distinguish is as follows:

If it can be presented on the image panel, it is a real image; Otherwise, it is an imaginary image.

Optical differences:

The virtual image is defocused, while the real image is focused (along the direction of light propagation) Since the human eye is equivalent to a set of lenses, it can focus the defocused light, so the human eye can see both the real image and the virtual image.

But this is not the case for the presentation plate, which does not produce a clear out-of-focus image.

As a result, virtual images cannot be rendered on the presentation panel.

I have found a way to distinguish between virtual and real images, so please follow me to understand the characteristics of virtual images and real images.

Real image: The light emitted by the object point is refracted by the lens, and all the refractive lines can converge at one point, which is called the real image point of the object point, and the set of all the real image points is called the image of the object. The characteristics of the real image are: the convergence of the actual light, the inverted, the opposite side, can be formed on the screen.

Virtual image: The light emitted by the object point, the intersection point of the reverse extension line of the refractive line refracted by the lens is called the virtual image point of the object point, and its set is called the virtual image of the object. The characteristics of the virtual image are: it is not the convergence of actual light, upright, and the same side cannot be the imaging law of the concave mirror on the screen.

Imaging principle: The image formed by the reflection or refraction of the light emitted by the object is called the "real image" after being reflected or refracted by the optical elements.

If the light emitted by an object is reflected or refracted by an optical element and diverged, the light rays are extended in reverse and intersect to form a "virtual image".

Undertaking method: "virtual image" can be directly ** with eyes**, but can not be accepted with light screen, "real image" can be undertaken with light screen or directly with eyes**.

Imaging position: "Real image" In reflection imaging, the object and the image are on the same side of the mirror, and in refractive imaging, the object image is on the opposite side of the lens.

In reverse imaging, the object and image are on the opposite side of the mirror, and in refractive imaging, the object image is on the same side of the lens.

There are many applications of convex lenses into real images, such as camera lenses and lenses of the human eye, and the real images are received by image sensors and retina; The lens of the projector is also a convex lens, and the imaging can be carried out by the screen. In order to solve the problem of inverted real images, the imaging of the digital camera and the human eye is processed by a microcomputer and the human brain respectively, so that the final thing seen is upright. For projectors, turn the picture back at ** to make the projection look upright.

The differences between virtual images and real images include differences in imaging principles, imaging properties, and reception methods.

1. The imaging principle is different, the image formed by the convergence of the light emitted by the object through the optical device is the real image, and the image formed by the light divergence after the optical device and the reverse extension and intersection is called the virtual image.

2. The difference in the nature of imaging is that the real image is inverted, and the virtual image is upright.

3. The difference in the receiving method of beam socks: the real image can be seen by the eyes and received by the light screen, while the virtual image can only be seen by the eyes and cannot be received by the light screen.

Imaging Rules:

The virtual image is a physical word, and if the beam is divergent, then it is the intersection of the reverse extension of the actual ray. Its rendezvous point is called the "virtual image" of the object. Virtual images cannot be achieved by actual light, so they cannot be taken over by light screens.

The light emitted by the object point is refracted by the lens, and the intersection point of the reverse extension line of its reflection line is called the virtual image point of the object point, and its set is called the virtual image of the object. The image formed by the concave mirror reflected or refracted by the convex lens can be displayed on the screen, so it is called a real image. The light source is outside the primary focus for the real image.

The above content reference: Encyclopedia - Virtual Image.