Concave Lens

One of the most important discoveries made by humans is the lens. Although it is impossible to establish when or how the lens was found, it is obvious that ancient people realised at some time that they could alter light using a piece of glass. Humans, for concave lens examples, employed lenses to make distant items appear closer, small objects appear larger, and fuzzy objects appear clearer (i.e. magnifying glasses and corrective lenses). Convex and Concave lenses are the two types of Spherical lenses.
If both surfaces of a lens are convex, it is called biconvex (or double convex, or just convex). The lens is biconvex if both surfaces have the same radius of curvature. Biconcave refers to a lens with two concave sides (or just concave). The lens is plano-convex or plano-concave depending on the curvature of the other surface if one of the surfaces is flat. Convex-concave or meniscus lenses have one convex and one concave side. This is the most frequent type of lens used in corrective lenses.

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1. What is concave lens? Define concave lens.
2. The formula for a concave lens
3. Uses of concave lens

What is concave lens? Define concave lens.

Concave lens definition (concave definition) and Concave lens meaning (concave meaning): A concave lens is a lens that diverges a straight light beam from the source to create a reduced, upright virtual picture. Concave lenses feature at least one curved surface inside. A concave lens is also known as a diverging lens because it is shaped round inwards in the centre and bulges outwards through the edges, causing light to diverge. They are used to cure myopia .

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What types of images are formed by concave lenses?

Only imaginary pictures are created by concave lenses. There will be no true images because the rays never converge after being refracted. All concave lens images will be virtual, decreased, and upright, and will be discovered between the F and the lens. A concave lens is also known as a diverging lens.

The formula for a concave lens

The concave lens formula is used to determine the nature and position of the image created by the lens. The following is the lens formula:

1/f=1/v+1/u

Where:

f is the focal length,

v is the image's distance from the centre,

u is the object's distance from the centre.

Similarly, the image magnification is provided by the equation,

M=hi/ho=v/u

Where:

M is the magnification,

hi is the image height,

ho is the object height.

Uses of concave lens

1. Spectacles are the first thing that comes to mind while thinking of lenses. Concave lenses are commonly used in spectacles to correct myopia (nearsightedness). Myopia affects people's ability to view distant objects. This occurs as the distance between the eye lens and the retina of a myopic person increases, causing light rays to collide considerably before they reach the retina's surface, resulting in no picture being formed on the retina, and the person seeing a blurred image of the far-away object. This can be remedied by inserting a concave lens in front of the nearsighted eye, which distributes the light and increases the focal length, allowing the picture to form on the retina. As a result, a person can see far away.

2. Peepholes are small lenses fitted on the walls or doors to allow you to see who is outside. Concave lenses are used in peepholes, allowing for a better view of the items outside the door. The majority of peepholes have three concave lenses and one convex lens. We can see the person outside the door through a peephole, but the person outside cannot see us. A person staring through the peephole from the outside can only get a magnified image of a very small portion of the light coming from the inside of the room due to the design of the concave lenses used in the peepholes.
3. Telescopes: Telescopes with only convex lenses produce distorted and hazy views from time to time. Concave lenses, as well as convex lenses, are employed in telescopes to remedy this anomaly. Concave lenses are put in front of the eyepieces of telescopes to assist focus the image more effectively, resulting in a crisp magnified image.
4. Laser Scanners: Many optical devices that utilise a laser beam, such as printers, scanners, and some medical equipment, use concave lenses. Laser beams have a very high intensity and are concentrated on a specific location, which might pose problems with optical systems. Concave lenses are employed because they disperse light and spread it over a larger region, improving the performance of laser beam systems.
5. Cameras: Only convex lenses are used in these cameras, which results in distorted images and a high risk of chromatic aberration. Chromatic aberration is an optical problem that arises when a convex lens fails to bring distinct colour wavelengths to the same focal plane; a focal plane is a plane perpendicular to the lens's major axis that passes through the focal point. Because a concave lens increases the focal length of the lens system and so minimises chromatic aberration, we can overcome the problem of chromatic aberration by utilising a concave lens in conjunction with a convex lens in cameras.
6. Flashlights: When parallel light rays released by a source collide with the surface of a concave lens, the light diverges on the other side, resulting in greater radii of the light source and a broader light spread. This is why concave lenses are commonly employed in flashlights. It's also utilised in car headlights since it can diverge light over greater distances, allowing the driver can see distant vehicles well at night.
7. Binoculars: The image supplied by the binoculars appears to be three-dimensional because, due to the space between our eyes, we see two images at slightly different angles; these two images merge, and we get a three-dimensional representation of the item. Both a concave and a convex lens are used in binoculars. The objective lens, which captures the initial image, is a concave lens, and the eyepiece is a convex lens. The objective lens collects light from the item and puts it into focus, while the eyepiece magnifies the image of the object.

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