Pronounced fruh-NELL. A type of flat lens, usually a thin sheet of plastic or glass with embossed or engraved concentric rings in its surface.
Such lenses tend to distribute light evenly over the surface. Theyre commonly used on high-brightness viewfinder screens, overhead projectors, etc. The lens design was invented by French physicist Augustin Fresnel (1788-1827), who used them in lighthouses.
Entry last updated 2002-04-08. Term 539 of 1487.
Previous term: freelance.
Next term: front nodal point.