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A peephole, peekhole, spyhole, doorhole, magic eye, magic mirror or door viewer is a small, round opening through a door from which a viewer on the inside of a dwelling may "peek" to see directly outside the door. The lenses are made and arranged in such a way that viewing is only possible in one direction. The opening is typically no larger than the diameter of a dime (0.7 inches, 18 mm).
View through a peepholeBarack Obama looking through the Oval Office door peepholeDoor viewer in the gate of Vaxholm Fortress
In a door, usually for apartments or hotel rooms, a peephole enables to see outside without opening the door nor revealing one's presence. Glass peepholes are often fitted with a fisheye lens to allow a wider field of view from the inside.[1]
Preventing inside viewabilityedit
Simple peepholes may allow people outside to see inside. A fisheye lens offers little visibility from the outside, but that can be defeated using a peephole reverser. Some peepholes have a shutter that falls down on the hole when nobody inside is holding it. Digital peepholes have a camera outside and an LCD screen inside, without any information going from the inside to the outside.
Another design to prevent people outside from seeing in involves the outside-facing lens projecting an image onto a semi-opaque frosted or ground glass screen. An inside viewer can see the other side of the door from an arm's length away, rather than by peering through a small hole, while the frosted glass finish makes it impossible for someone to look through from the outside. There are drawbacks to the projection method: the area to be viewed must be well lit, and installation requires a much larger hole in the door than a traditional peephole.
Referencesedit
^ Peephole Is One Way Viewer, Popular Science, July 1950, p. 153, right-side.
Look up peephole in Wiktionary, the free dictionary.
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January 01, 1970
peephole, system, down, song, system, down, album, computer, compiler, techniques, peephole, optimization, this, article, multiple, issues, please, help, improve, discuss, these, issues, talk, page, learn, when, remove, these, template, messages, this, article. For the System of a Down song see System of a Down album For the computer compiler techniques see peephole optimization This article has multiple issues Please help improve it or discuss these issues on the talk page Learn how and when to remove these template messages This article relies largely or entirely on a single source Relevant discussion may be found on the talk page Please help improve this article by introducing citations to additional sources Find sources Peephole news newspapers books scholar JSTOR October 2017 This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Peephole news newspapers books scholar JSTOR October 2017 Learn how and when to remove this message Learn how and when to remove this message A peephole peekhole spyhole doorhole magic eye magic mirror or door viewer is a small round opening through a door from which a viewer on the inside of a dwelling may peek to see directly outside the door The lenses are made and arranged in such a way that viewing is only possible in one direction The opening is typically no larger than the diameter of a dime 0 7 inches 18 mm View through a peephole Barack Obama looking through the Oval Office door peephole Door viewer in the gate of Vaxholm Fortress In a door usually for apartments or hotel rooms a peephole enables to see outside without opening the door nor revealing one s presence Glass peepholes are often fitted with a fisheye lens to allow a wider field of view from the inside 1 Preventing inside viewability editSimple peepholes may allow people outside to see inside A fisheye lens offers little visibility from the outside but that can be defeated using a peephole reverser Some peepholes have a shutter that falls down on the hole when nobody inside is holding it Digital peepholes have a camera outside and an LCD screen inside without any information going from the inside to the outside Another design to prevent people outside from seeing in involves the outside facing lens projecting an image onto a semi opaque frosted or ground glass screen An inside viewer can see the other side of the door from an arm s length away rather than by peering through a small hole while the frosted glass finish makes it impossible for someone to look through from the outside There are drawbacks to the projection method the area to be viewed must be well lit and installation requires a much larger hole in the door than a traditional peephole References edit Peephole Is One Way Viewer Popular Science July 1950 p 153 right side nbsp Look up peephole in Wiktionary the free dictionary nbsp Wikimedia Commons has media related to Peepholes Retrieved from https en wikipedia org w index php title Peephole amp oldid 1219327627, wikipedia, wiki, book, books, library,
