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Anti-reflective Coating
An antireflective, antiglare or anti-reflection (AR) coating is a type of optical coating applied to the surface of lens (optics), lenses, other optical elements, and photovoltaic cells to reduce reflection (physics), reflection. In typical imaging systems, this improves the efficiency since less light is lost due to reflection. In complex systems such as cameras, binoculars, telescopes, and optical microscope, microscopes the reduction in reflections also improves the Contrast (vision), contrast of the image by elimination of stray light. This is especially important in planetary astronomy. In other applications, the primary benefit is the elimination of the reflection itself, such as a coating on glasses, eyeglass lenses that makes the eyes of the wearer more visible to others, or a coating to reduce the glint from a covert viewer's binoculars or telescopic sight. Many coatings consist of transparent thin-film optics, thin film structures with alternating layers of contrasting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binoculars
Binoculars or field glasses are two refracting telescopes mounted side-by-side and aligned to point in the same direction, allowing the viewer to use both eyes (binocular vision) when viewing distant objects. Most binoculars are sized to be held using both hands, although sizes vary widely from opera glasses to large pedestal-mounted military models. Unlike a (monocular) telescope, binoculars give users a stereopsis, three-dimensional image: each eyepiece presents a slightly different image to each of the viewer's eyes and the parallax allows the visual cortex to generate an depth perception, impression of depth. Optical design evolution Galilean Almost from the invention of the telescope in the 17th century the advantages of mounting two of them side by side for binocular vision seems to have been explored. Most early binoculars used Galilean telescope, Galilean optics; that is, they used a convex lens, convex objective (optics), objective and a concave lens, concave eyepi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-reflective Coating Comparison
An antireflective, antiglare or anti-reflection (AR) coating is a type of optical coating applied to the surface of lenses, other optical elements, and photovoltaic cells to reduce reflection. In typical imaging systems, this improves the efficiency since less light is lost due to reflection. In complex systems such as cameras, binoculars, telescopes, and microscopes the reduction in reflections also improves the contrast of the image by elimination of stray light. This is especially important in planetary astronomy. In other applications, the primary benefit is the elimination of the reflection itself, such as a coating on eyeglass lenses that makes the eyes of the wearer more visible to others, or a coating to reduce the glint from a covert viewer's binoculars or telescopic sight. Many coatings consist of transparent thin film structures with alternating layers of contrasting refractive index. Layer thicknesses are chosen to produce destructive interference in the beams refl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Destructive Interference
In physics, interference is a phenomenon in which two coherent waves are combined by adding their intensities or displacements with due consideration for their phase difference. The resultant wave may have greater amplitude (constructive interference) or lower amplitude (destructive interference) if the two waves are in phase or out of phase, respectively. Interference effects can be observed with all types of waves, for example, light, radio, acoustic, surface water waves, gravity waves, or matter waves as well as in loudspeakers as electrical waves. Etymology The word ''interference'' is derived from the Latin words ''inter'' which means "between" and ''fere'' which means "hit or strike", and was used in the context of wave superposition by Thomas Young in 1801. Mechanisms The principle of superposition of waves states that when two or more propagating waves of the same type are incident on the same point, the resultant amplitude at that point is equal to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contrast (vision)
Contrast is the difference in luminance or color that makes an object (or its representation in an image or display) visible against a background of different luminance or color. The human visual system is more sensitive to contrast than to absolute luminance; thus, we can perceive the world similarly despite significant changes in illumination throughout the day or across different locations. The maximum contrast of an image is termed the contrast ratio or dynamic range. In images where the contrast ratio approaches the maximum possible for the medium, there is a ''conservation of contrast''. In such cases, increasing contrast in certain parts of the image will necessarily result in a decrease in contrast elsewhere. Brightening an image increases contrast in darker areas but decreases it in brighter areas; conversely, darkening the image will have the opposite effect. Bleach bypass reduces contrast in the darkest and brightest parts of an image while enhancing luminance contr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Pollution
Light pollution is the presence of any unwanted, inappropriate, or excessive artificial Visible spectrum, lighting. In a descriptive sense, the term ''light pollution'' refers to the effects of any poorly implemented lighting sources, during the day or night. Light pollution can be understood not only as a phenomenon resulting from a specific source or kind of pollution, but also as a contributor to the wider, collective impact of various sources of pollution. Although this type of pollution can exist throughout the day, its effects are magnified during the night with the contrast of the sky's darkness. It has been estimated that 83% of the world's people live under light-polluted skies and that 23% of the world's land area is affected by skyglow. The area affected by artificial illumination continues to increase. A major side effect of urbanization, light pollution is blamed for compromising health, disrupting ecosystems, and spoiling aesthetic environments. Studies show that ur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optician
An optician is an individual who fits glasses or contact lenses by filling a refractive prescription from an optometrist or ophthalmologist. They are able to translate and adapt ophthalmic prescriptions, dispense products, and work with accessories. There are several specialties within the field. Types Dispensing optician or ophthalmic dispenser A dispensing optician is anyone who prepares, fits, and dispenses prescription lenses, spectacles, glasses, contact lenses, or any other type of vision-correcting optical device to the intended user. They may interpret optical prescriptions issued by an ophthalmologist, optometrist, or physician for the lab optician who fabricates vision-correcting optical lenses. They also measure inter-ocular or pupillary distances, vertex distances, pupil fitting heights, and frame angles to determine the proper position of vision-correcting lenses. In addition, they adapt, modify, or align frames with vision-correcting lenses to the face of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Cell
A solar cell, also known as a photovoltaic cell (PV cell), is an electronic device that converts the energy of light directly into electricity by means of the photovoltaic effect.Solar Cells chemistryexplained.com It is a type of photoelectric cell, a device whose electrical characteristics (such as Electric current, current, voltage, or Electrical resistance and conductance, resistance) vary when it is exposed to light. Individual solar cell devices are often the electrical building blocks of solar panel, photovoltaic modules, known colloquially as "solar panels". Almost all commercial PV cells consist of crystalline silicon, with a market share of 95%. Cadmium telluride thin-film solar cells account for the remainder. The common single-junction silicon solar cell can produce a maximum open-circuit voltage o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camera Lens
A camera lens, photographic lens or photographic objective is an optical lens (optics), lens or assembly of lenses (compound lens) used in conjunction with a camera body and mechanism to Imaging, make images of objects either on photographic film or on other media capable of storing an image Photosensitivity, chemically or Image sensor, electronically. There is no major difference in principle between a lens used for a still camera, a video camera, a telescope, a microscope, or other apparatus, but the details of design and construction are different. A lens might be permanently fixed to a camera, or it might be interchangeable lens camera, interchangeable with lenses of different focal lengths, apertures, and other properties. While in principle a simple lens, simple convex lens will suffice, in practice a compound lens made up of a number of optical lens elements is required to correct (as much as possible) the many optical aberrations that arise. Some aberrations will be prese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corrective Lens
A corrective lens is a transmissive optical device that is worn on the eye to improve visual perception. The most common use is to treat refractive errors: myopia, hypermetropia, astigmatism, and presbyopia. Glasses or "spectacles" are worn on the face a short distance in front of the eye. Contact lenses are worn directly on the surface of the eye. Intraocular lenses are surgically implanted most commonly after cataract removal but can be used for purely refractive purposes. Prescription of corrective lenses Corrective lenses are typically prescribed by an ophthalmologist or an optometrist. The prescription consists of all the specifications necessary to make the lens. Prescriptions typically include the power specifications of each lens (for each eye). Strengths are generally prescribed in quarter- diopter steps (0.25 D), because most people cannot generally distinguish between smaller increments (e.g., eighth-diopter steps / 0.125 D). The use of improper corr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voigtlander Lenses 75mm, 50mm, And 15mm
Voigtländer () was a significant long-established company within the optics and photographic industry, headquartered in Braunschweig, Germany, and today continues as a trademark for a range of photographic products. History Voigtländer was founded in Vienna, Archduchy of Austria, in 1756, by . Voigtländer produced mathematical instruments, precision mechanical products, optical instruments, including optical measuring instruments and opera glasses, and is the oldest name in cameras. Early beginnings Johann Christoph Voigtländer (November 19, 1732 in Leipzig – June 27, 1797 in Vienna), the son of a carpenter, came to Prague in 1755, and to Vienna in the same year, and worked from 1757 to 1762 in the workshop of Meinicke, who produced mathematical instruments. Through Johann Voigtländer's skilful achievements, the Minister of State of the Habsburg monarchy— Prince Wenzel von Kaunitz, drew attention to Voigtländer and Empress Maria Theresa of Austria granted Voigtl� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. The photons of ultraviolet have greater energy than those of visible light, from about 3.1 to 12 electron volts, around the minimum energy required to ionize atoms. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack sufficient energy, it can induce chemical reactions and cause many substances to glow or fluoresce. Many practical applications, including chemical and biological effects, are derived from the way that UV radiation can interact with organic molecules. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared
Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those of red light (the longest waves in the visible spectrum), so IR is invisible to the human eye. IR is generally (according to ISO, CIE) understood to include wavelengths from around to . IR is commonly divided between longer-wavelength thermal IR, emitted from terrestrial sources, and shorter-wavelength IR or near-IR, part of the solar spectrum. Longer IR wavelengths (30–100 μm) are sometimes included as part of the terahertz radiation band. Almost all black-body radiation from objects near room temperature is in the IR band. As a form of EMR, IR carries energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
