lens: Quick Facts

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Last updated

Nov. 12, 2026

News •

Lens were humiliated by Como. The pain continued against Marseille • Nov. 9, 2026, 1:09 PM ET (The Guardian)

Lens fans banned from Liverpool game in Champions League for throwing flares that stopped play • Oct. 27, 2026, 5:59 PM ET (Houston Chronicle)

Photos and Videos

Diagram showing how convex and concave lenses form images: Convex lenses create real, inverted images at different positions depending on object distance, or a virtual, upright image if the object is close. Concave lenses always form a virtual, upright, and smaller image between the object and the lens. Light rays and image locations are illustrated for each scenario.

Diagram showing cross-sections of common lenses on the left, with three converging lenses above and three diverging lenses below. On the right, light rays are shown passing through a converging lens, focusing at point F on the principal axis, and through a diverging lens, spreading outward as if originating from focal point F. Labels indicate axis, focal point, focal length, and focal plane.

curve generator

Side-by-side photos of roses in a glass vase by a window show glare on the tabletop through an unpolarized lens and reduced glare through a polarized lens.

lens aberrations

Diagram of a double convex lens bending diverging rays from a star-shaped light source so they converge toward an eye.

convex and concave lenses: bending light

focal length of a lens

Gauss theory of lenses

Diagram showing how a convex lens magnifies an object, with rays passing through the lens to create an enlarged virtual image of a light bulb, as seen by an eye positioned at the focus.

How lenses and mirrors affect light and vision

Understand how a pinhole focuses light and why lenses are better than pinholes

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Topics

focal length relay lens Abbe sine condition bifocal lens anastigmatic lens achromatic lens cylindrical lens converging lens mirror lens objective lens Mirror diffraction grating filter prism collimator microscope aberration Binoculars periscope stereoscopy

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Key People

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Giuseppe Campani

Italian inventor

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John Henry Dallmeyer

British manufacturer