The difference between mirror and lens lies in how light reflects when falls over their surface. When light interacts with any surface, mainly two things happen; Reflection and Refraction. The main difference between mirror and lens is that image forms by reflection, as the light falls on a mirror. In lens, the image is formed by refraction. Let us now understand more about the difference between mirror and lens by studying in detail.
Table of content
1 What is Mirror?
2 What is Lens?
3 Difference Between Mirror and Lens
3.1 Mirror
3.2 Lens
3.2.1 FAQs about mirror and lens:
What is Mirror?
The mirror is the piece of glass that is polished on one side and reflects light falling on it. The more polished, or shiny, the more light will “bounce off” it’s surface. One of the surfaces is typically coated with a metal amalgam, which reflects a clear image. In a mirror narrow beam of light that incides on its surface bounces in a single direction, without scattering.
What is Lens?
A lens is a combination of two prisms, sometimes base up or base down. It is a transparent optical medium that converges or diverges a light beam by working on the principle of refraction. The lens is simple or compound (a combination of many simple lenses).
Difference Between Mirror and Lens
Difference between Mirror and lens
ImportantDifference between Mirror and lens
| Parameter | Mirror | Lens |
| Definition | The mirror is glass with one side silvery backing produces an image by reflection on only one surface. | The lens is a transparent substance that produces images by refraction in any surface of the two surfaces. |
| Curvature | It can be plane or curved. | Always curved at one or two surfaces. |
| Law | Laws of reflection | Laws of refraction |
| Types | There are two types: concave and convex | There are six types of lenses. |
| Focal point | Plane mirror has no focal point | It has 2 focal points for each type of lens |
| Manufacture | From glass or metal | From glass or plastic |
| Uses | Mirror tiles, dressing table, periscope, camera, looking glass, solar cooker | Refraction unit, spectacle glass, flashlight, telescope, microscope |
We must learn in detail to find out more after studying the difference between mirror and lens.
Mirror
A mirror is a piece of glass or polished metal surface coated with a metal film that reflects light without diffusion and produces an image of an object when placed in front of it. It forms a specular reflection. A plane mirror gives a real-looking undistorted image, while a curved mirror may distort, magnify, or reduce the image in various ways.
Mirrors can be classified in many ways; including by shape, support and reflective materials, manufacturing methods, and intended application.
Principle
1) Plane surface mirror- When parallel beams of light are reflected on a plane surface, the reflected rays will be parallel too.
2) If the reflecting surface is concave, the reflected beams will be convergent, at least to some extent, and for some distance from the surface.
3) convex mirror- It will reflect parallel rays towards divergent directions.
Mirrors are usually manufactured by either polishing a naturally reflective material, such as speculum metal or by applying a reflective coating to a suitable polished substrate. Two types of coating are widely in use, silvering and dielectric coating. Mirrors are commonly used for personal grooming, rearview mirror, one-way mirrors and windows, signaling, projectors, solar power, telescope, sculpture, decors, etc.
Lens
It is a piece of glass or other transparent material with curved sides for concentrating or dispersing light rays. It has two opposite surfaces either both curved or one curved and one plane. The curves are almost always spherical. A lens forms images of objects situated in front of it.
Lenses are classified according to their two surfaces as biconvex, plano-convex, concavo-convex (converging meniscus), biconcave, Plano concave, and convexo-concave (diverging meniscus).
Principle
” Different speed of light in the lens than in the surrounding air, causes refraction, i.e, an abrupt bending, of a light beam. It occurs both where the beam enters the lens and where it comes out from the lens into the air.”
During the manufacture of lenses, slabs of glass are cut with a glass saw or slitting disk or the pieces may be heated to softness and rolled to a round shape. Then it is pressed in a mold to the desired size and any required curvature of the surfaces. The surfaces are then ground, or lapped, to the final form.
Lenses are commonly in use in a magnifying glass, as spectacle correction for refractive error, projectors, camera, to generate solar energy, radio astronomy, etc.
FAQs about mirror and lens:
1) Why do telescopes use mirrors instead of lenses?
Ans- Most telescopes work by using curved mirrors to gather and focus light from the night sky. As mirrors are lighter, and they are easier than lenses to make a smooth combination.
2) Where is the concave lens useful?
Ans- Concave lenses cause light to spread out, resulting in a smaller image for the viewer. Concave lenses use includes eyeglasses and contacts, flashlights, peepholes, binoculars, telescopes, and in photography.
References
Certainly! The difference between mirrors and lenses revolves around how they manipulate light through reflection and refraction. Let's delve into the concepts mentioned in the article:
What is a Mirror?
Definition: A mirror is a surface—typically glass or polished metal—coated with a reflective material, like a metal film, that reflects light without scattering. This reflection forms an image. It can be plane or curved, with variations like concave and convex mirrors.
Principle: Mirrors work based on the laws of reflection. Plane mirrors reflect light so that incident and reflected rays are parallel. Concave mirrors converge reflected rays, while convex mirrors diverge them.
Manufacture: Mirrors are made by polishing naturally reflective materials or applying reflective coatings (such as silvering or dielectric coatings) to suitable substrates. They have various applications from personal grooming to telescopes and solar power.
What is a Lens?
Definition: A lens is a transparent medium, often glass, with curved surfaces that refract light. It can be biconvex, plano-convex, concavo-convex, biconcave, Plano concave, or convexo-concave.
Principle: Lenses work based on the principle of refraction, caused by the difference in the speed of light between the lens and surrounding air. This refraction bends light beams as they pass through the lens.
Manufacture: Lenses are made by cutting slabs of glass, heating them to softness, shaping them in molds, and grinding the surfaces to their final form. They find uses in magnifying glasses, corrective spectacles, projectors, and solar energy generation.
Differences Summarized:
- Formation of Image: Mirrors create images through reflection; lenses form images through refraction.
- Curvature: Mirrors can be plane or curved; lenses always have curved surfaces.
- Laws Involved: Mirrors operate based on the laws of reflection; lenses work based on the laws of refraction.
- Types: Mirrors have types like concave and convex; lenses have six types based on their curvature.
- Focal Point: Mirrors (plane) have no focal point; lenses have two focal points for each type.
- Manufacture: Mirrors are made from glass or metal with reflective coatings; lenses are made from glass or plastic.
FAQs:
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Why do telescopes use mirrors instead of lenses?
- Mirrors are lighter and easier to manufacture with smooth surfaces compared to lenses.
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Where is the concave lens useful?
- Concave lenses cause light to spread out, resulting in a smaller image for the viewer. They are used in eyeglasses, telescopes, photography, etc.
The provided references offer further insights into mirrors and lenses, providing comprehensive information for deeper understanding.
This breakdown covers the concepts outlined in the article, focusing on the fundamental differences and applications of mirrors and lenses.
