Transparent glass or plastic that has been formed and polished to form a certain shape, usually spherical. When a beam of light reaches the area between the air and the lens, a part of this light is always reflected. The remaining light passes into the lens and alters its propagation direction, i.e. the light is refracted. The incorporation of various lenses (converging and diverging lenses) creates a lens system. When optimally arranged, they allow the subject to be presented correctly on the image plane.
| Lens adapter Adapter between the end of the camera’s lens and the lens converter. A step-up-ring is also a type of lens adapter. |
| Lens hood Made from metal or plastic, the hood fits on the end of the lens to shade the front lens element from incidental light, which could otherwise cause reflections, glare and ghosting. |
| Lens system Group of lenses (sometimes just one lens) that enable the sharpest and brightest pictures to be taken. Often simply referred to as the lens or objective. There are various lenses available such as wide-angle, normal, macro, and tele with fixed focal distances as well as zoom lenses with adjustable focal distances. |
