Search results
Results from the WOW.Com Content Network
The word lens comes from lēns, the Latin name of the lentil (a seed of a lentil plant), because a double-convex lens is lentil-shaped. The lentil also gives its name to a geometric figure. [a] Some scholars argue that the archeological evidence indicates that there was widespread use of lenses in antiquity, spanning several millennia. [1]
A magnifying glass is a convex lens that is used to produce a magnified image of an object. The lens is usually mounted in a frame with a handle. A magnifying glass can be used to focus light, such as to concentrate the Sun's radiation to create a hot spot at the focus for fire starting. A plastic Fresnel lens sold as a TV-screen magnifier
A burning glass or burning lens is a large convex lens that can concentrate the Sun's rays onto a small area, heating up the area and thus resulting in ignition of the exposed surface. Burning mirrors achieve a similar effect by using reflecting surfaces to focus the light.
The use of a convex lens to form an enlarged/magnified image was most likely described in Ptolemy's Optics (which survives only in a poor Arabic translation). Ptolemy's description of lenses was commented upon and improved by Ibn Sahl (10th century) and most notably by Alhazen (Book of Optics, c. 1021).
A magnifying glass, which uses a positive (convex) lens to make things look bigger by allowing the user to hold them closer to their eye. A telescope , which uses its large objective lens or primary mirror to create an image of a distant object and then allows the user to examine the image closely with a smaller eyepiece lens, thus making the ...
A simple microscope uses a lens or set of lenses to enlarge an object through angular magnification alone, giving the viewer an erect enlarged virtual image. [1] [2] The use of a single convex lens or groups of lenses are found in simple magnification devices such as the magnifying glass, loupes, and eyepieces for telescopes and microscopes.
Convex lens - a lens in which one or two sides is curved or bowed outwards. Light passing through the lens is converged (or focused) to a spot behind the lens. Convex optimization - a subfield of optimization, studies the problem of minimizing convex functions over convex sets. The convexity property can make optimization in some sense "easier ...
Simple lenses are lenses consisting of a single element. Lenses in this section may overlap with lens designs in other sections, for example the Wollaston landscape lens is a single element and also a camera lens design. Basic types. Biconcave lens; Biconvex lens; Convex-concave lens; Plano concave lens; Plano convex lens; Meniscus lens; Designs