Optical devices

300px|thumb|right|Leica Camera|Leica camera (1950s) 300px|thumb|right|Hasselblad 500 C/M with Zeiss lens A camera is an instrument used to capture and store images and videos, either digitally via an electronic image sensor, or chemically via a light-sensitive material such as photographic film. As a pivotal technology in the fields of photography and videography, cameras have played a significant role in the progression of visual arts, media, entertainment, surveillance, and scientific research. The invention of the camera dates back to the 19th century and has since evolved with advancements

optical device that projects an image of its surroundings on a screen

thumb|right|Principle of the periscope. The periscope on the left uses mirrors whereas the right uses prisms. a Mirrors b Prisms c Observer's Eye

camera used for electronic motion picture acquisition

300px|thumb|upright=1.7 |The first prototype ammonia maser in front of its inventor [[Charles H. Townes. The ammonia nozzle is at left in the box, the four brass rods at center are the quadrupole state selector, and the resonant cavity is at right. The 24 GHz microwaves exit through the vertical waveguide Townes is adjusting. At bottom are the vacuum pumps.]] thumb|right|260px|A hydrogen radio frequency discharge, the first element inside a #Hydrogen maser|hydrogen maser (see description below)

A photoresistor (also known as a light-dependent resistor, LDR, or photo-conductive cell) is a passive component that decreases in resistance as a result of increasing illuminance (light) on its sensitive surface, in other words, it exhibits photoconductivity. A photoresistor can be used in light-sensitive detector circuits and light-activated and dark-activated switching circuits acting as a semiconductor resistance. In the dark, a photoresistor can have a resistance as high as several megaohms (MΩ), while in the light, it can have a resistance as low as a few hundred ohms. If incident light

Technique used to improve performance of optical systems by compensating for distortions

thumb|Coronagraph image of the Sun A coronagraph is a telescopic attachment designed to block out the direct light from a star or other bright object so that nearby objects – which otherwise would be hidden in the object's bright glare – can be resolved. Most coronagraphs are intended to view the corona of the Sun, but a new class of conceptually similar instruments (called stellar coronagraphs to distinguish them from solar coronagraphs) are being used to find extrasolar planets and circumstellar disks around nearby stars as well as host galaxies in quasars and other similar objec

telescope which is used to focus light from the visible part of the electromagnetic spectrum

thumb|300px|Old Zeiss (company)|Zeiss pocket stereoscope with original test image right|thumb|A common Underwood & Underwood Stereoscope

instrument using light waves for image viewing

thumb|right|Acer inc.|Acer projector, 2012 thumb|Digital Light Processing|DLP type home theatre projector in use A projector or image projector is an optical device that projects an image (or moving images) onto a surface, commonly a projection screen. Most projectors create an image by shining a light through a small transparent lens, but some newer types of projectors can project the image directly, by using lasers. A virtual retinal display, or retinal projector, is a projector that projects an image directly on the retina instead of using an external projection screen.

thumb|300px|Example of a particle collimator A collimator is a device which narrows a beam of particles or waves. “To narrow” can mean either to cause the directions of motion to become more aligned in a specific direction (i.e., make collimated light or parallel rays), or to cause the spatial cross section of the beam to become smaller (beam limiting device).

optical device used as a drawing aid by artists

device for alignment and aiming of a weapon

thumb|150px|A , f/5.3 astrograph at Lowell Observatory (a refractor with a 3 element [[Cooke triplet lens) used in the discovery of Pluto.]] thumb|150px|A double astrograph consisting of two astrographs and a central guide scope on display at Landessternwarte Heidelberg-Königstuhl observatory. thumb|The Bruce double astrograph at the Landessternwarte Heidelberg-Königstuhl observatory. thumbnail|This is a modern amateur Newtonian telescope|Newtonian astrograph, specifically designed for astrophotography.

transparent display presenting data within normal sight lines of the user

thumb|200px|Conceptual animation of the dispersion (or breaking down) of light thumb|200px|Monochromator in an x-ray beamline at the [[Advanced Photon Source, Argonne National Laboratory.]]

thumb| Miniature Speed Graphic, early 1940s, 2¼ × 3¼ inch format, with focal plane shutter and four different viewfinding means: a spring back with ground glass under a flip-up cover, simple optical viewfinder on top, Kalart rangefinder on side, and sports finder consisting of flip-up wire at lensboard and flip-up peepsight on top

device that amplifies an optical signal

Astronomical instrument used to measure movements or variations in the brightness of celestial objects

arrangement of mirrors that forms a standing wave cavity resonator for light waves

thumb|Two different types of phototubes A phototube or photoelectric cell is a type of gas-filled or vacuum tube that is sensitive to light. Such a tube is more correctly called a 'photoemissive cell' to distinguish it from photovoltaic or photoconductive cells. Phototubes were previously more widely used but are now replaced in many applications by solid state photodetectors. The photomultiplier tube is one of the most sensitive light detectors, and is still widely used in physics research.

laser interferometer designed to measure angular velocity

A milliradian (SI-symbol mrad, sometimes also abbreviated mil or mils) is an SI derived unit for angular measurement which is defined as a thousandth of a radian (0.001 radian). Milliradians are used in adjustment of firearm sights by adjusting the angle of the sight compared to the barrel (up, down, left, or right). Milliradians are also used for comparing shot groupings, or to compare the difficulty of hitting different sized shooting targets at different distances. When using a scope with both mrad adjustment and a reticle with mrad markings (called an "mrad/mrad scope"), the shooter c

one of the compounds formed between silver and one of the halogens

medical device, microscope with a light source that can be projected into a linear beam

electronic sensor that measures infrared light

Type of non-magnifying optical sight where the aiming point light is projected onto a partially reflective sighting window

highly sensitive semiconductor electronic device

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vacuum tube device for increasing the intensity of available light

captures information about the light field emanating from a scene; that is, the intensity of light in a scene, and also the direction that the light rays are traveling in space

spectral line source used in physics and chemistry

image capture method

Optical component

thumb|right thumb|Moviola Model D (1927) with a microscope attachment (left) by Gaertner Scientific Corporation from 1940 A Moviola () is a device that allows a film editor to view a film while editing. It was the first machine for motion picture editing when it was invented by Iwan Serrurier in 1924.

detection single parties and photons

used in waveguides

thumb|240px|right|A low quality fiberscope observing the inside of an antique clock mechanism. Note how individual fibers are discernable, as each fiber only relays one part of the image.

thumb|Schematic view of a rigid borescope thumb|Borescope in use, showing typical view through the device

An aquascope (also called bathyscope) is an underwater viewing device. It is used to view the underwater world often from dry land or a boat. It eliminates the water surface glare and allows viewing as far as water clarity and light permit. The underwater viewer can be used for observing reefs, checking boat moorings, secchi disks and other survey work. It is also used as educational tool to watch plants, creatures and habitats underneath the surface of rivers, lakes and seas.

viewing device that is illuminated from below through a translucent cover

surveillance device that uses a laser beam to detect sound vibrations in a distant object

solid-state photodetector

telescope focusing device

type of optical resonator

uses the acousto-optic effect to diffract and shift the frequency of light using sound waves

optical polarization rotator based on the Faraday effect

optical test for curved mirrors

thumb|Carlo Ponti's Megalethoscope The megalethoscope is a larger version (mega-) of the alethoscope, (Italian: alethoscopio, from the Greek “true”, “exact” and “vision”) which it largely superseded, and both are instruments for viewing single photographs with a lens to enlarge and to create some illusion of three-dimensionality. They were used to view photographic albumen prints that were coloured, perforated and mounted on a curved frame. Night effects were achieved when viewing pictures in transmitted light from a fitted oil or kerosine lamp and a daytime version of the same scene was seen

optical multiplexer component

used in optical projection

type of image sensor

Type of device

non-magnifying gun sight where the reticle (aiming point) is a hologram

Type of opitcal sight

device that can quickly change the phase of an optical beam according to an applied voltage

USP-1 or "Tyulpan" (From Russian: Унифицированный Стрелковый Прицел, первый образец, Unifitsirovannyj Strelkovyj Pritsel, pervyj obrazets, "Unified Firearm Sight, first model, GRAU index 1P29) is a Soviet/Russian universal optic sight, used on the AK rifle family (AKMN, AK-74N, AK-74M, AK-101, AK-102, AK-105), the RPK-74N, the PKMN and the PKP "Pecheneg" and is designed for quick-mounting and quick-detaching. Compared with an open mechanical sight, the effectiveness of firing at targets is increased 1.2 to 2 times, and the time taken to conduct a firing session is reduced by 60%. == Design ==