Difference Between Real Image and Virtual Image for JEE Main 2024

Do you know what a mirror image is? Well! When the light rays coming from an object appear to meet at a point after reflection or refraction, the point may be defined as an image. The word object in the definition can be anything that emits light rays.

As light is emanating from an object in a variety of directions, an image is formed. Some of these rays which represent the light reach the mirror's surface and reflect off the surface as per the laws of reflection.

Two Types of Images Formed are:

• Real Image

• Virtual Image

Do you know what significance these images have and in what terms they vary?

This page will help us understand the different types of images formed on mirror along with their distinction.

Real and Virtual Images: Differences using Concave/Convex Mirrors

Now, let us understand what real and virtual images are:

• Real Image

A compilation of focus points of light rays emitting from an object defined as an image in terms of optics. An assortment of focus points made by the converging rays is known as a real image, whereas the collection of focus points made by the extension of diverging rays is known as the virtual image. In simplistic terms, an image located in the plane of convergence for the light rays emitted from an object known as a real image. 

When rays converge, real image occurs, and when rays only appear to diverge, virtual image occurs. By usage of concave mirrors and converging lenses, a real image can be produced, but on the condition that the object is placed further away from the mirror/lens than the focal point, and the real image is inverted. As the object nears the focal point, the image will move towards infinity, and when the object surpasses the focal point, the image becomes virtual and is upright. Space is not the same as from the object to the lenses.

When the light rays after refraction or reflection meet at a point, it exists in reality, meaning a real image can be placed on the screen. The backward extension of refracted or reflected light rays is true for a virtual image; that is, it doesn't exist in reality.

For a convex lens, placing an object at or near a distance equal to or less than the focal length will give you a real image. This is similar to what you would get in the case of a concave mirror except for the object placed at a distance equal to or less than the focal point; you will get a real image.

As per the below diagram, a real image is formed by a convex lens, and one real image is formed by a concave mirror.

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Example of Real Image

The most common example for a real image is the image on the cinema screen as the object is being projected on the screen with the help of a projector. This reflects the image on the screen, which plays the object to be imaged by human eyes. The image is created on a detector in the rear of a camera or the image produced on the retina of the eyeball (they focus light through an internal convex lens). In the diagrams below, real rays of light are represented by full solid lines, or generalized rays of light are represented by dashed lines.

• Virtual Image

A range of focus points formed by the converging rays is known as a real image, while the collection of focus points made by the extension of diverging rays is known as the virtual image. A virtual image is formed by tracing real rays that arise from an optical device like a mirror or lens, backward to apparent origins of ray divergences. In the diagram of the optical system, the dotted lines represent the conventional virtual ray. 

Since the rays don't converge, a virtual image cannot be created on a screen, but a real image can be produced on a screen as the rays converge on a real location. People can see the image as a real image can be projected onto a diffusely reflecting screen(the image on the screenplays as an object to be imaged by human eyes)

An example of a virtual image formed by a concave mirror and plane mirror given below:

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Here, we notice the following things:

• AB = is the object

• A'B' = is the Image

• OX - is the distance of the image from the mirror

• OY - is the distance of the object from the mirror

• For a plane mirror, OY=OX

Hence, the distance between the image and the object is OX + OY = 2OY(as OX = OY)

Example of Virtual Image

Reflection in the mirror is the best example of a virtual image. By the intersecting rays, the real images are produced, and by diverging rays, the virtual images are produced. On-screen real images projected while virtual images cannot—two opposite lenses convex and concave from the real images.

A plane mirror forms a virtual image placed behind the mirror. The light from the source only exists in the mirror, even if the rays of light come from behind the mirror. In the plane mirror, the image is not magnified, meaning that the size of the object and image are the same, and it appears to be far behind the mirror as the object is before the mirror.

From the above text on real and virtual images, we understand that a real image is the collection of focus points made in actual by converging rays, whereas the collection of focus points made by extensions of diverging rays is called the virtual image. In simple words, it is an image that is located in the plane of convergence for the light rays that originate from a given object.