Question

why we should use concave lens

Answer 1

↪Concave lens Converges the right rays from a diametrical distance at its focus.

➡Figures shows how

➡Mechanism:--
Diverging light rays are made parallel by a convex lens. But when the parallel light rays pass through a concave lens, they diverge (spread out) again.

➡Main purpose:-

↪Curving inward, concave lenses cause light to spread out, resulting in a smaller image for the viewer.

➡Despite being less useful than convex lenses, concave lenses have several uses, including in eyeglasses and contacts, flashlights, peepholes, binoculars, telescopes, and in photography.

➡Dont forget to follow me ;)

Answer 2

Convex lenses have a significant drawback when used in optical applications like binoculars and telescopes. Light is often passed through a convex lens incorrectly, causing the image to appear with incorrect colors. Concave lenses are used in binoculars and telescopes so what you see is the correct color.