Mirrors. Classification and image formation

08/05/2026

The online mirror simulations on this page allow us to check in a practical way how mirrors work and how depending on their curvature (flat, concave or convex) the reflected image is different. We will discover how mirrors are classified in physics and how images are formed in a mirror.

This Thematic Unit is part of our Physics collection

Concave Mirror

Spherical mirror with the surface curved inward that can converge light rays at a focal point.

Convex Mirror

Spherical mirror with the surface curved outward that diverges light rays and widens the field of view.

Focal Length

Path that light travels from the objective to the point where the sharp image is formed.

Focal Point (Focus)

Point where parallel reflected rays converge in a concave mirror (or from which they appear to originate in a convex one).

Lateral Inversion

Phenomenon in plane mirrors where the right side of the object appears on the left side of the reflected image.

Plane Mirror

Smooth reflective surface that produces virtual, upright images of the same size as the object.

Real Image

Image formed by the actual convergence of reflected rays, which can be projected onto a surface.

Virtual Image

Image formed by the extension of reflected rays that appears to be located behind the mirror.

What are mirrors

Mirrors are objects that reflect light in a specular way, which means that they keep the reflected image with high fidelity. They have been used for centuries for a variety of purposes, from decoration to scientific and technological applications.

Classification of mirrors in physics

Mirrors in physics are mainly classified according to the shape of their reflecting surface, which determines the characteristics of the image they produce and their practical applications. The main types are described below:

Plane mirror

A plane mirror has a completely smooth and flat surface. It reflects light following the law of reflection, forming virtual images, straight and of the same size as the object, but laterally inverted. This type of mirror is the most common and is used in everyday life, in bathroom mirrors, dressing rooms and basic optical devices

Concave mirror

A concave mirror has an inward curved surface, similar to the inside of a sphere. Concave mirrors can form real or virtual images, depending on the position of the object with respect to the focus and the center of curvature. They have the ability to concentrate light at a focal point, so they are used in telescopes, reflectors, lamps and some makeup mirrors to magnify the image.

Convex mirror

A convex mirror has an outwardly curved surface, like the outside of a sphere. This type of mirror always generates smaller, upright, virtual images with a wide field of view. They are ideal for use in vehicle mirrors, surveillance and security, as they allow large areas to be viewed from a single point.

In addition to their shape, mirrors can be classified by the material of manufacture (glass, metal, plastics with special coatings) and by their specific application (dielectric, parabolic, spherical mirrors, among others). In scientific research and engineering, there are mirrors designed for very precise tasks, such as mirrors used in lasers, fiber optics and advanced optical systems.

This variety in classification allows mirrors to be fundamental tools in physics, engineering, medicine, art and everyday life, adapting to specific needs for the control and manipulation of light.

Mirror applications

Mirrors have a wide range of practical applications. In the domestic field, they are used in dressing tables, bathrooms and as decorative elements in the home. They are also essential in the fashion industry and in photography for evaluating personal appearance and creating images.

In science and technology, mirrors play a crucial role in optical instruments such as microscopes, telescopes, periscopes and cameras. They are also used in the construction of lasers and in fiber optics to direct and reflect light through cables. Mirrors have also been the subject of artistic and cultural exploration. They have been used in art to create illusions and visual effects, and in literature and film to symbolize introspection and perception.

In summary, the online mirror simulations on this page help us in a practical way to understand how mirrors work.

Concave Mirror

Spherical mirror with the surface curved inward that can converge light rays at a focal point.

Convex Mirror

Spherical mirror with the surface curved outward that diverges light rays and widens the field of view.

Focal Length

Path that light travels from the objective to the point where the sharp image is formed.

Focal Point (Focus)

Point where parallel reflected rays converge in a concave mirror (or from which they appear to originate in a convex one).

Lateral Inversion

Phenomenon in plane mirrors where the right side of the object appears on the left side of the reflected image.

Plane Mirror

Smooth reflective surface that produces virtual, upright images of the same size as the object.

Real Image

Image formed by the actual convergence of reflected rays, which can be projected onto a surface.

Virtual Image

Image formed by the extension of reflected rays that appears to be located behind the mirror.

Explore the exciting STEM world with our free, online, simulations and accompanying companion courses! With them you’ll be able to experience and learn hands-on. Take this opportunity to immerse yourself in virtual experiences while advancing your education – awaken your scientific curiosity and discover all that the STEM world has to offer!

Mirror simulations

Plane mirror principle

This simulation explains how a plane mirror works. See what happens when the gaze point of the eye changes.

Plane mirror lab

Types of mirrors. Convex mirror or concave mirror

Observe in this simulation how the image is generated in a convex mirror or concave mirror and how the equation changes depending on the focal length.

Concave mirror lab

Convex mirror lab

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Test your knowledge

What are mirrors, and how are they classified in physics?

Mirrors are surfaces capable of reflecting light specularly, meaning they preserve the relative direction of rays and allow the formation of sharp images. Their operation is based on the laws of reflection, which state that the angle of incidence equals the angle of reflection and that the incident ray, the reflected ray and the normal lie in the same plane. In physics, mirrors are mainly classified according to the shape of their reflective surface: plane, concave and convex. Plane mirrors produce virtual, upright images of the same size. Concave mirrors can generate real or virtual images depending on the object’s position, while convex mirrors always produce virtual and reduced images.

How are images formed in plane, concave and convex mirrors?

In a plane mirror, the image is formed by extending the reflected rays behind the mirror. It is virtual, upright, the same size as the object and laterally inverted. In a concave mirror, image formation depends on the object’s position relative to the focal point and the center of curvature. If the object is far from the center, the image is real, inverted and reduced; if it is between the focus and the mirror, the image is virtual, upright and magnified. In a convex mirror, the reflected rays diverge and the image is always virtual, upright and smaller. These differences give each mirror type specific applications in optics, safety and magnification devices.

Why do curved mirrors distort or change the size of images?

Curved mirrors distort or change image size because their surface does not reflect light in parallel as a plane mirror does. In a concave mirror, rays converge toward a point, which can make the image appear larger or even inverted. In a convex mirror, rays spread out, so the image appears smaller and with a wider field of view. These differences come from the curvature of the surface, which changes the direction of the reflected rays.

What differences exist between a concave mirror and a convex mirror?

A concave mirror has a surface curved inward and can form real or virtual images depending on the object’s position. It also concentrates light at a focal point, allowing image magnification or light focusing, as in reflectors. A convex mirror has a surface curved outward and always produces virtual, upright and smaller images. Its main advantage is its wide field of view, making it useful in vehicle mirrors and surveillance systems.

What are mirrors used for in everyday life and technology?

Mirrors are used at home for viewing oneself, applying makeup or decorating spaces. In science and technology they are essential in microscopes, telescopes, cameras and periscopes. They are also used in lasers and optical fiber to direct light precisely. In security, convex mirrors allow wide‑area monitoring. In art and design they create visual effects and perspective illusions. Their ability to reflect light makes them versatile tools in many fields.