How a Lens Works

At its very simplest, a lens element is a (mostly) transparent element made of glass, plastic, or some other material, with one or two curved surfaces that bend (refract) the direction of light as it passes through. A curve that bulges outward (convex) causes the light to converge towards a single point of focus. A curve that bulges inward (concave) causes the light to diverge, instead.

Camera Components and Concepts - Lens

The basic components of a DSLR are described below. (Most of the components in a rangefinder are also found in a DSLR.)

Lens, Aperture, Shutter, Digital image sensor, Memory card, External flash

Lens

A lens is a series of sophisticated elements, usually glass, constructed to refract and focus the reflective light from a scene at a specific point—the digital image sensor.