materiały: Fresnel lens

Evidence: 100 • authority: 72

A Fresnel lens ( FRAY-nel, -⁠nəl; FREN-el, -⁠əl; or fray-NEL) is a type of composite compact lens which reduces the amount of material required compared to a conventional lens by dividing the lens into a set of concentric annular sections. The simpler dioptric (purely refractive) form of the lens was first proposed by Georges-Louis Leclerc, Comte de Buffon, and independently reinvented by the French physicist Augustin-Jean Fresnel (1788–1827) for use in lighthouses. The catadioptric (combining refraction and reflection) form of the lens, entirely invented by Fresnel, has outer prismatic elements that use total internal reflection as well as refraction to capture more oblique light from the…

Evidence: 88 • authority: 72

Augustin-Jean Fresnel (10 May 1788 – 14 July 1827) was a French civil engineer and physicist whose research in optics led to the almost unanimous acceptance of the wave theory of light, fully supplanting Newton's corpuscular theory, from the late 1830s until the end of the 19th century. He is perhaps better known for inventing the catadioptric (reflective/refractive) Fresnel lens and for pioneering the use of "stepped" lenses to extend the visibility of lighthouses, saving countless lives at sea. The simpler dioptric (purely refractive) stepped lens, first proposed by Count Buffon and independently reinvented by Fresnel, is used in screen magnifiers and in condenser lenses for overhead proj…

Evidence: 22 • authority: 80

Georges-Louis Leclerc, Comte de Buffon

Evidence: — • authority: 88

Transverse Chromatic Aberration of an Ophthalmic Lens Degrades Visual Performance more than Dioptric Defocus. The development of ophthalmic lenses in the last few years is characterized by the use of aspheric surfaces for a flattering of base curve and by the use of high refractive index materials. The design of aspheric lenses allows a good control of peripheral monochromatic aberrations. Recent studies (Simonet et al., 1992; Gresset et al., 1993) have shown that oblique astigmatism and mean oblique power error are generally not greater than ±0.50D for an ocular rotation of 300. However such a dioptric defocus affects visual performance measured by contrast sensitivity function (Charman, 1…