What are real and virtual images?

The real image is the image formed by the convergence of actual light, and the virtual image is the image formed by the convergence of actual light in the opposite extension line.

Real image:

A real image is an image that can be presented on the screen. It is formed by the convergence of actual light, which can make the negative film sensitive, so it is called real image.

The light screen can accept the real image, and a clear image can be received by placing the light screen at the position of the image. Photography or film projection should use the principle of real images. When people look at the virtual image, light still enters their eyes, but the light does not come from the virtual image, but is reflected or refracted by optical elements. It's just that people have the experience of "light travels in a straight line" and think it is emitted from a virtual image.

Virtual image:

The light emitted by an object is reflected or refracted by a concave mirror and a convex lens, and if it is divergent light, it forms an image at the intersection of extension lines with opposite directions. The virtual image cannot be displayed on the screen, nor can it make the photographic film sensitive, but it can be seen by the naked eye. Such as images in microscopes and telescopes.

Imaging function:

The light emitted by the object is refracted or reflected by the optical system, and then converged again to form an inverted image similar to the original object. The light screen can accept the real image, and a clear image can be received by placing the light screen at the position of the image. Photography or film projection should use the principle of real images. Compared with the original, the real image is always upside down and will be upside down.

The difference between real image and virtual image:

(1) The imaging principle is different:

The light emitted by an object is reflected or refracted by an optical element, and then converged to form an image called a real image, which is the intersection of actual light. In convex lens imaging, all real images are inverted. If the light emitted by an object diverges after being reflected or refracted by an optical element, the image formed by the intersection of them after extending in the opposite direction is called a virtual image.

(2) Different ways of undertaking:

Virtual images can be viewed directly with eyes, but cannot be accepted by light screen; The real image can be accepted by the light screen, or it can be viewed directly with the eyes. Virtual images can be formed by reflection or refraction, for example, a plane mirror forms an equal virtual image and a convex lens forms an enlarged virtual image.

(3) Different imaging positions:

Real image In reflection imaging, the object and image are on the same side of the mirror, while in refraction imaging, the object and image are on the opposite side of the lens. Virtual image In reflection imaging, the object and image are on different sides of the mirror, while in refraction imaging, the object and image are on the same side of the lens.