Difference between Concave and Convex Lens

Difference between Concave and Convex Lens

A convex lens or converging lens focuses the light rays to a specific point whereas a concave lens or diverging lens diverges the light rays. A lens is a transparent material (either curved or flat surface) based on the principles of refraction. Concave lenses and convex lenses are often used together known as Concave – Convex lens. When these lenses are combined they produce sharper images. Most of the eyeglass lenses use combinations of convex and concave lenses. Cameras, telescopes, and microscopes which use different lens helping us to see the world in a better way.

Difference between Concave and Convex Lens

Concave Lens

Convex Lens

A concave lens is thinner in the middle and thicker at the edges.

A convex lens is thicker in the middle and thinner at the edges.

It is also known as Diverging Lens

It is also known as Converging Lens

Used in Glasses, some telescopes, spy holes in doors, etc. It is also used for the correction of problem in short sight

Used in camera, focus sunlight, overhead projector, projector microscope, simple telescope, magnifying glasses, etc. It is also used for the correction of problem in long sight.

Negative Focal Length

Positive Focal Length

It diverges the incident rays away from the principal axis.

It converges the incident rays towards the principal axis.

Types of Image Formed

Concave Lens

Convex Lens

The image formed is upright, virtual, and smaller size than the object. The position of the image formed is in between the lens and the object regardless of object’s position

The image formed is inverted, real, and smaller than the object when the object is placed at Focus. The image formed is inverted, real, and same size as the object when the object is placed at 2F. The image formed is inverted, real, and larger than the object when the object is placed between 2F and F. No image is formed when the object is placed at Focus (F). The image formed is upright, Virtual, and larger than the object when the object is placed on the same side of the lens.


Practise This Question

Name the constellation in the figure.