Convex Lens vs. Concave Lens: What's the Difference?

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Key difference

The main difference between convex lens and the concave lens is that the light rays which are passing through the convex lens will merge at a particular point known as a focal point while concave lens will diverge the light rays around that are passing through it.

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Convex Lens vs. Concave Lens

The word “lens” is derived from “Lens”, i.e. a Latin name of the “lentil” (A plant with lens-shaped seeds). A lens is a transparent optical device that merges or disperses the light beams passing through it by refraction. It is made up of glass or plastic etc. It is widely used in microscopes, telescopes, cameras and even in correcting vision problems etc. Based on shape, convex and concave lens are two types of lenses. Convex lens is the lens that will merge the light rays passing through it at a specific point while Light beams passing through the concave lens will diverge.

Comparison chart

BasisConvex LensConcave Lens
DefinitionIt is defined as the lens which merges the light passing through it at the focal point.It is defined as the lens which diverges the light passing through it.
LightConvergesDiverges
ShapeThis lens is thicker at the center and thinner at the edges.It is thicker at edges as compared to the center.
ObjectThe object will appear closer and larger.The object will appear smaller and beyond.
ImageThe image will be real and inverted.The image will be erect, virtual and diminished.
Position of ImageBoth the Image and the object are on the same side of the lens.The object is on one side of the lens while the image is on the other side.
The position of the focal pointIn front of the lensOn the back side of the lens.
Focal lengthIts focal length is positive.Its focal length is negative.
UsesUse to correct long sightednessUse to correct short sightedness.
BendingBow outwardBow inward
ExamplesIt is used as a camera lens.It is used as a side mirror of vehicles.
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What is Convex Lens?

A convex lens is also recognized as a converging lens because it converges all the parallel light rays passing through it at a specific point known as a focal point. The distance between focal point and center of the lens is known as focal length. A convex lens has a positive focal length because the focal point is present in front of the convex lens. It is thicker at the center as compared to its edges. It magnifies the object and makes a closer and larger image of it. So, it is used to cope with long sightedness. It produces the real and inverted image of the object.

Example

Lenses of a camera are convex lenses, i.e. focus light rays on the object being captured.

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What is Concave Lens?

A concave lens is also recognized as a diverging lens because it diverges the beam of light passing through it. The light rays seem to be diverging from a specific point known as the focal point. The focal length of the concave lens is negative because its focal point is present on the back of the lens. This lens is thicker at the edges as compared to the center. It bends the beams outward and causes divergence. The concave lens makes the object look smaller and farther and forms an erect, virtual and Diminished image of it. It is used to control short-sightedness.

Example

It is used as side mirrors of vehicles and in movie projectors to spread the image.

Key Differences

  1. A convex lens is a lens that Converges the light rays passing through it at the focal point whereas the concave lens is the lens that diverges the beam of light passing through the lens.
  2. Convex lens bent outward while concave lens bent
  3. A convex lens has thin edges while the concave lens is thinner at the center.
  4. The real and inverted image is formed through the convex lens, but a concave lens formed an erect, virtual and diminished image.
  5. The focal length of the convex lens is positive whereas that of the concave lens is negative.
  6. A convex lens is used to cope with short-sightedness while the concave lens is used to cope with long sightedness.
  7. Through the convex lens, the object will appear closer and larger while the concave lens shows smaller and farther object.

Comparison Video

Conclusion

According to the above discussion, it is concluded that Convex lens is a lens that converges the light rays passing through it and form a real and inverted image of the object while concave lens diverged the beam of light and formed an erect, virtual and diminished image of the object.