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Viewing Instrument
A viewing instrument is a type of optical instrument that is used to assist viewing or visually examining an object or scenery Types * binoculars * contact lenses * cystoscope * electrotachyscope * endoscope * eyeglasses * fibrescope * finderscope * fluoroscope * gastroscope * gonioscope * kaleidoscope * kinetoscope * laryngoscope * magnifying glass * microscope * ophthalmoscope * otoscope * periscope * phenakistoscope also phenakistiscope * praxinoscope * Rotoscope * spectroscope * spotting scope * stereoscope * stroboscope * tachistoscope * telescope * teleidoscope * viewfinder In photography, a viewfinder is what the photographer looks through to compose, and, in many cases, to focus the picture. Most viewfinders are separate, and suffer parallax, while the single-lens reflex camera lets the viewfinder use the main ... {{div col end Optical instruments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Instrument
An optical instrument (or "optic" for short) is a device that processes light waves (or photons), either to enhance an image for viewing or to analyze and determine their characteristic properties. Common examples include periscopes, microscopes, telescopes, and cameras. Image enhancement The first optical instruments were telescopes used for magnification of distant images, and microscopes used for magnifying very tiny images. Since the days of Galileo and Van Leeuwenhoek, these instruments have been greatly improved and extended into other portions of the electromagnetic spectrum. The binocular device is a generally compact instrument for both eyes designed for mobile use. A camera could be considered a type of optical instrument, with the pinhole camera and camera obscura being very simple examples of such devices. Analysis Another class of optical instrument is used to analyze the properties of light or optical materials. They include: *Interferometer for measuring the in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microscope
A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisible to the eye unless aided by a microscope. There are many types of microscopes, and they may be grouped in different ways. One way is to describe the method an instrument uses to interact with a sample and produce images, either by sending a beam of light or electrons through a sample in its optical path, by detecting photon emissions from a sample, or by scanning across and a short distance from the surface of a sample using a probe. The most common microscope (and the first to be invented) is the optical microscope, which uses lenses to refract visible light that passed through a thinly sectioned sample to produce an observable image. Other major types of microscopes are the fluorescence microscope, electron microscope (both the transmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleidoscope
A teleidoscope is a kind of kaleidoscope, with a lens and an open view, so it can be used to form kaleidoscopic patterns from objects outside the instrument, rather than from items installed as part of it. Invented by John Lyon Burnside III and Harry Hay, the patent was filed in 1970 and granted in 1972. The lens at the end of the tube is not an optical requirement, but protects the internals of the teleidoscope. A spherical ball lens A ball is a round object (usually spherical, but can sometimes be ovoid) with several uses. It is used in ball games, where the play of the game follows the state of the ball as it is hit, kicked or thrown by players. Balls can also be used ... is often used. An advantage of using a sphere is that it will not press flat against the object being viewed, which would block all light and result in no image being seen. External links *Kaleidoscopes Periods & Styles Brewster Kaleidoscope Society References Optical toys American invention ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telescope
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe distant objects, the word ''telescope'' now refers to a wide range of instruments capable of detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors. The first known practical telescopes were refracting telescopes with glass lenses and were invented in the Netherlands at the beginning of the 17th century. They were used for both terrestrial applications and astronomy. The reflecting telescope, which uses mirrors to collect and focus light, was invented within a few decades of the first refracting telescope. In the 20th century, many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s. Etymology The word ''telescope'' was coin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tachistoscope
A tachistoscope is a device that displays an image for a specific amount of time. It can be used to increase recognition speed, to show something too fast to be consciously recognized, or to test which elements of an image are memorable. Projection tachistoscopes use a slide or transparency projector equipped with the mechanical shutter system typical of a camera. The slide is loaded, the shutter locked open, and focusing and alignment are adjusted, then the shutter is closed. When ready for the test, a shutter speed is selected, and the shutter is tripped normally. History The first tachistoscope was originally described by the German physiologist A.W. Volkmann in 1859. Samuel Renshaw used it during World War II in the training of fighter pilots to help them identify aircraft silhouettes as friend or foe. Applications Before computers became universal, tachistoscopes were used extensively in psychological research to present visual stimuli for controlled duratio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stroboscope
A stroboscope, also known as a strobe, is an instrument used to make a cyclically moving object appear to be slow-moving, or stationary. It consists of either a rotating disk with slots or holes or a lamp such as a flashtube which produces brief repetitive flashes of light. Usually, the rate of the stroboscope is adjustable to different frequencies. When a rotating or vibrating object is observed with the stroboscope at its vibration frequency (or a submultiple of it), it appears stationary. Thus stroboscopes are also used to measure frequency. The principle is used for the study of rotating, reciprocating, oscillating or vibrating objects. Machine parts and vibrating string are common examples. A stroboscope used to set the ignition timing of internal combustion engines is called a timing light. Mechanical In its simplest mechanical form, a stroboscope can be a rotating cylinder (or bowl with a raised edge) with evenly spaced holes or slots placed in the line of si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereoscope
A stereoscope is a device for viewing a stereoscopic pair of separate images, depicting left-eye and right-eye views of the same scene, as a single three-dimensional image. A typical stereoscope provides each eye with a lens that makes the image seen through it appear larger and more distant and usually also shifts its apparent horizontal position, so that for a person with normal binocular depth perception the edges of the two images seemingly fuse into one "stereo window". In current practice, the images are prepared so that the scene appears to be beyond this virtual window, through which objects are sometimes allowed to protrude, but this was not always the custom. A divider or other view-limiting feature is usually provided to prevent each eye from being distracted by also seeing the image intended for the other eye. Most people can, with practice and some effort, view stereoscopic image pairs in 3D without the aid of a stereoscope, but the physiological depth cues result ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spotting Scope
A spotting scope is a compact high-power telescope optimized for detailed observation of distant objects. They are used as portable optical enhancement devices for various outdoor activities such as birdwatching, skygazing and other naturalist activities, for hunting and target shooting to verify a marksman's shot placements, for tactical ranging and surveillance, and for any other application that requires higher magnification than ordinary binoculars (typically 20× to 60×). The light-gathering power and resolution of a spotting scope is determined by the diameter of the objective lens, typically between . The larger the objective, the more massive and expensive the telescope. The optical assembly has a small refracting objective lens, an internal image-erecting system, and an eyepiece that is usually removable. The image-erecting system may use relay lenses, prisms such as Porro or roof prisms, or a catadioptric system of the Schmidt or Maksutov design. Spotting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectroscope
An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's intensity but could also, for instance, be the polarization state. The independent variable is usually the wavelength of the light or a unit directly proportional to the photon energy, such as reciprocal centimeters or electron volts, which has a reciprocal relationship to wavelength. A spectrometer is used in spectroscopy for producing spectral lines and measuring their wavelengths and intensities. Spectrometers may operate over a wide range of non-optical wavelengths, from gamma rays and X-rays into the far infrared. If the instrument is designed to measure the spectrum on an absolute scale rather than a relative one, then it is typically called a spectrophotometer. The majority o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotoscope
Rotoscoping is an animation technique that animators use to trace over motion picture footage, frame by frame, to produce realistic action. Originally, animators projected photographed live-action movie images onto a glass panel and traced over the image. This projection equipment is referred to as a rotoscope, developed by Polish-American animator Max Fleischer, and the result is a rotograph. This device was eventually replaced by computers, but the process is still called rotoscoping. In the visual effects industry, ''rotoscoping'' is the technique of manually creating a matte for an element on a live-action plate so it may be composited over another background. Chroma key is more often used for this, as it is faster and requires less work, but rotoscopy provides a higher level of accuracy and is often used in conjunction with chroma-keying. It may also be used if the subject is not in front of a green (or blue) screen, or for practical or economic reasons. Technique R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praxinoscope
The praxinoscope was an animation device, the successor to the zoetrope. It was invented in France in 1877 by Charles-Émile Reynaud. Like the zoetrope, it used a strip of pictures placed around the inner surface of a spinning cylinder. The praxinoscope improved on the zoetrope by replacing its narrow viewing slits with an inner circle of mirrors, placed so that the reflections of the pictures appeared more or less stationary in position as the wheel turned. Someone looking in the mirrors would therefore see a rapid succession of images producing the illusion of motion, with a brighter and less distorted picture than the zoetrope offered. Variations Reynaud introduced the Praxinoscope-Théâtre in 1879. This was basically the same device, but it was hidden inside a box to show only the moving figures within added theatrical scenery. When the set was assembled inside the unfolded box, the viewer looked through a rectangular slot in the front, onto a plate with a transparent m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenakistoscope
The phenakistiscope (also known by the spellings phénakisticope or phenakistoscope) was the first widespread animation device that created a fluent illusion of motion. Dubbed and ('stroboscopic discs') by its inventors, it has been known under many other names until the French product name became common (with alternative spellings). The phenakistiscope is regarded as one of the first forms of moving media entertainment that paved the way for the future motion picture and film industry. Like a GIF animation, it can only show a short continuous loop. Etymology and spelling When it was introduced in the French newspaper ''Le Figaro'' in June 1833, the term 'phénakisticope' was explained to be from the root Greek word ''phenakistikos'' (or rather from φενακίζειν ''phenakizein''), meaning "deceiving" or "cheating", and ὄψ ''óps'', meaning "eye" or "face", so it was probably intended loosely as 'optical deception' or 'optical illusion'. The term phénakisticope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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