periscope


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periscope

(pĕr`ĭskōp) [Gr.,=view around], instrument to enable a person to see objects not in his direct line of vision or concealed by some intervening body. Its essential parts are a tube, prisms, lenses, mirrors, and an eyepiece. The image is received in one mirror and reflected through the tube with its lenses to a mirror visible to the viewer. Periscopes used in submarines are so arranged that they can be turned to permit a view of the entire horizon, with built-in rangefinders and typically six times magnification. Submarine periscopes are of noncorrosive metal, have tubes up to 30 ft (9.1 m) long and about 6 in. (15 cm) in diameter (only a small section projects above the water), and may be withdrawn into the submarine. Many smaller types of periscopes are used in trenches and tanks. With the development of fiber optics, periscopes (known as cystoscopes or endoscopes) have become useful in medicine.

Periscope

 

an optical instrument for viewing from such military shelters as trenches and dugouts, from tanks, and from submarines. Many periscopes permit measurement of horizontal and vertical angles on the terrain and also range-finding. The design and optical characteristics of a periscope are determined by its purpose, place of installation, and the depth from which observations are to be made.

The simplest periscope is the vertical type, consisting of a vertical sighting tube and two mirrors. Set at 45° angles to the axis of the tube, the mirrors form an optical system that refracts light rays coming from the observed object and directs them toward the observer’s eye. Periscopes in which right-angle prisms are installed in the tube instead of mirrors are common, as are telescopic lens systems and rotating systems, which can be used to obtain an erect magnified image. The field of vision of a periscope with low magnification (up to 1.5 power) is about 40°; it usually decreases with greater magnification. Certain types of periscopes give panoramic vision.

periscope

[′per·ə‚skōp]
(optics)
An optical instrument used to provide a raised line of vision where it may not be practical or possible, as in entrenchments, tanks, or submarines; the raised line of vision is obtained by the use of mirrors or prisms within the structure of the item; it may have single or dual optical systems.
A thin astigmatic lens which approximates a meniscus shape and has a base curve of ±1.25 diopters.
References in periodicals archive ?
Brandhuber said that while the sub was rushing preparations to go to periscope depth, he was engaged in an ''internalized debate,'' balancing what he was observing with what he had heard of Waddle's good reputation and the Greeneville crew's professionalism.
I followed the lookouts down the ladder butstopped at the conning tower, positioning myself between the pair of periscopes. The other men continued below to the control room and their various battle stations.
Read: (https://www.ibtimes.com/twitter-periscope-live-360-video-how-use-new-feature-2466786) Twitter Launches 360 Degree Video Functionality On Periscope
This report includes a complete technology and cost analysis of the Huawei P30 Pro folded optic periscope camera module that includes the CIS die, the lens module, the prism, the voice coil motor (VCM) and the housing.
We might see a periscope lens in one of Xiaomi's upcoming flagship devices, most probably on a Mix device, as it is the flagship smartphone series of the Chinese giant.
Under terms of the agreement, Quad will purchase Periscope for USD 132.5m.
Social media firm Twitter has been experimenting a new audio-only broadcast feature through its Periscope platform for a few weeks, and the company has recently made it publicly available for all iOS users of the main Twitter app and its live streaming app Periscope.
Twitter has allowed users to start and embed live broadcasts within their tweets since 2015 when it bought video streaming service Periscope. Users can now stream directly from the iOS app or download a separate Periscope app, whichever they prefer.
"From the court order, it is clear that beIN / Digiturk knows exactly which three accounts violated its rights, and its legal representatives could instead report these accounts directly to Periscope and get them suspended immediately.
Twitter's live-streaming service Periscope will be blocked during Turkey's top football league matches, an Istanbul court has said in a landmark ruling.
Summary: Washington [United States], July 28 (ANI): As part of its ongoing efforts of clamping down on abusers across its network, Twitter will start blocking accounts of repeat offenders who post abusive comments during Periscope live streams.
Walking up Wembley Way, John snapped up World Cup memorabilia, including a periscope (right), which will be sold today by Newcastle auctioneers Anderson and Garland.