binoculars是什么意思oculars在线翻译读音

Binoculars

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AtypicalPorroprismbinoculardesign

Binoculartelescopes,orbinoculars(alsoknownasfieldglasses),aretwoidentical

ormirror-symmetricaltelescopesmountedside-by-sideandalignedtopoint

accuratelyinthesamedirection,allowingtheviewertousebotheyes(binocular

vision)esizedtobeheldusingbothhands,

althoughtherearemuchlargertypes.

Unlikeamonoculartelescope,abinoculargivesusersathree-dimensionalimage:the

twoviews,presentedfromslightlydifferentviewpointstoeachoftheviewer\'seyes,

snoneedtocloseorobstruct

oneeyetoavoidconfusion,asisusualwithmonoculartelescopes.

Contents

[hide]

1Opticaldesign

o1.1Galileanbinoculars

o1.2Prismbinoculars

1.2.1Porroprismbinoculars

1.2.2Roofprismbinoculars

1.2.3Relativeadvantagesofporroprismandroofprism

binoculars

2Opticalparameters

3Opticalcoatings

o3.1Anti-reflectivecoatings

o3.2Roofprismphasecorrectioncoating

o3.3Roofprismmetallicmirrorcoating

o3.4Roofprismdielectricmirrorcoating

o3.5Marketingtermsusedtodenotecoatings

4Mechanicaldesign

o4.1Focusingandadjustment

o4.2Imagestabilization

o4.3Alignment

5Applications

o5.1Generaluse

o5.2Military

o5.3Astronomical

6Manufacturers

7Seealso

8Notes

9References

10Externallinks

[edit]Opticaldesign

Galileanbinoculars

[edit]Galileanbinoculars

Almostfromtheinventionofthetelescopeinthe17thcenturytheadvantagesof

mountingtwoofthemsidebysideforbinocularvisionseemstohavebeenexplored.[1]

MostearlybinocularsusedGalileanoptics;thatistheyusedaconvexobjectiveanda

ileandesignhastheadvantageofpresentinganerect

imagebuthasanarrowfieldofviewandisnotcapableofveryhighmagnification.

Thistypeofconstructionisstillusedinverycheapmodelsandinoperaglassesor

theaterglasses.

[edit]Prismbinoculars

Animprovedimageandhighermagnificationcanbeachievedinaconstruction

binocularsemployingKeplerianoptics,wheretheimageformedbytheobjectivelens

isviewedthroughapositiveeyepiecelens(ocular).Thisconfigurationhasthe

redifferentwaysofcorrectingthese

disadvantages.

[edit]Porroprismbinoculars

DoublePorroprismdesign

NamedafterItalianopticianIgnazioPorrowhopatentedthisimageerectingsystemin

1854andlaterrefinedbymakerslikeCarlZeissinthe1890s,[1]binocularsofthistype

u

featureresultsinbinocularsthatarewide,withobjectivelensesthatarewellseparated

rismdesignshavetheaddedbenefitoffolding

theopticalpathsothatthephysicallengthofthebinocularsislessthanthefocal

lengthoftheobjectiveandwiderspacingoftheobjectivesgivesbettersensationof

depth.

Abbe-Koenig\"roofprism\"design

[edit]Roofprismbinoculars

Binocularsusingroofpri小石城山记阅读答案 smsmayhaveappearedasearlyasthe1870sinadesignby

AchilleVictorEmileDaubresse.[2][3]Mostroofprismbinocularsuseeitherthe

Abbe-Koenigprism(namedafterErnstKarlAbbeandAlbertKoenigandpatentedby

CarlZeissin1905)orSchmidt-Pechanprism(inventedin1899)designstoerectthe

veobjectivelensesthatareapproximatelyin

linewiththeeyepieces.

[edit]Relativeadvantagesofporroprismandroofprismbinoculars

Roof-prismsdesignscreateaninstrumentthatisnarrowerandmorecompactthan

-prismbinoculars

willinherentlyproduceabrighterimagethanroof-prismbinocularsofthesame

magnification,objectivesize,andopticalquality,becausetheroof-prismdesign

employssilveredsurfacesthatreducelighttransmissionby12%to15%.Roof-prisms

designsalsorequiretightertolerancesasfarasalignmentoftheiropticalelements

(collimation).Thisaddstotheirexpensesincethedesignrequiresthemtousefixed

prismsbinocularsoccasionallyneedtheirprismsetstobere-alignedtobringthem

edalignmentinroof-prismdesignsmeansthebinoculars

normallywon\'tneedre-collimation.[4]

[edit]Opticalparameters

talkpagefordetails.(April

2009)

Parameterslistedontheprismcoverplatedescribinga7powermagnification

binocularwitha50mmObjectivediameteranda372-footFieldofviewat1000

yards.

Binocularsareusuallydesignedforthespecificapplicationforwhichtheyare

ifferentdesignscreatecertainopticalparameters(someofwhich

maybelistedontheprismcoverplateofthebinocular).Thoseparametersare:

Magnification—Theratioofthefocallengthoftheeyepiecedividedintothefocal

lengthoftheobjectivegivesthelinearmagnifyingpowerofbinoculars(sometimes

expressedas\"diameters\").Amagnificationoffactor7,forexample,producesan

untofmagnification

-heldbinoculars

r

magnificationleadstoasmallerfieldofview.

Objectivediameter–Thediameteroftheobjectivelensdetermineshowmuchlight

uallyexpressedinmillimeters.

Itiscustomarytocategorizebinocularsbythemagnificationtheobjectivediameter;

Fieldofview—Thefieldofviewofabinocularisdeterminedbyitsopticaldesign.

Itisusuallynotatedinalinearvalue,suchashowmanyfeet(meters)inwidthwillbe

seenat1,000yards(or1,000m),orinanangularvalueofhowmanydegreescanbe

viewed.

Exitpupil—Binocularsconcentratethelightgatheredbytheobjectiveintoabeam,

theexitpupil,whosediameteristheobjectivediameterdividedbythemagnifying

imumeffectivelight-gatheringandbrightestimage,theexitpupil

shouldequalthediameterofthefullydilatedirisofthehumaneye—about7mm,

oneoflightstreamingoutofthebinocularislargerthanthe

pupilitisgoinginto,anylightlargerthanthepupiliswastedintermsofproviding

imeusethehumanpupilistypicallydilatedabout3

mm,arger7x50binocular

willproduceaconeoflightbiggerthanthepupilitisentering,andthislightwill,in

theday,ereforeseeminglypointlesstocarryaroundalarger

instrument.

However,alargerexitpupilmakesiteasiertoputtheeyewhereitcanreceivethe

light:seofplacement

helpsavoidvignetting,whichisadarkenedorobscuredviewthatoccurswhenthe

,itmeansthattheimagecanbequicklyfound

whichisimportantwhenlookingatbirdsorgameanimalsthatmoverapidly.A

narrowexitpupilbinocularmayalsobefatiguingbecausetheinstrumentmustbeheld

y,manypeople

usetheirbinocularsatdusk,inovercastconditions,andatnight,whentheirpupilsare

fort,

easeofuse,andflexibilityinapplications,largerbinocularswithlargerexitpupilsare

satisfyingchoiceseveniftheircapabilityisnotfullyusedbyday.

Eyerelief—Eyereliefisthedistancefromthereareyepiecelenstotheexitpupilor

eyepoint[5].Itisthedistancetheobservermustpositionhisorhereyebehindthe

gerthefocallengthofthe

eyepiece,larsmayhaveeyereliefrangingfromfew

iefcanbeparticularlyimportantfor

ofaneyeglassweareristypicallyfurtherfromtheeyepiece

whichnecessitatesalongereyereliefinordertostillseetheentirefieldofview.

Binocularswithshorteyereliefcanalsobehardtouseininstanceswhereitis

difficulttoholdthemsteady.

[edit]Opticalcoatings

[edit]Anti-reflectivecoatings

Mainarticle:Anti-reflectivecoating

nocular

Sinceabinocularcanhave16air-to-glasssurfaces,withlightlostateverysurface,

ghtstrikesaninterface

,atanair-glassinterface),

someofthelightistransmitted,ortofimage-formingoptical

instrument(telescope,camera,microscope,etc.),ideallynolightshouldbereflected;

insteadofforminganimage,lightwhichreachestheviewerafterbeingreflectedis

distributedinthefieldofview,andreducesthecontrastbetweenthetrueimageand

tioncanbereduced,butnoteliminated,byapplyingoptical

melightentersorleavesapieceofglass;about5%is

\"lost\"lightbouncesaroundinsidethebinocular,makingthe

atingseffectivelylowerreflectionlosses,which

mple,8x40binocularswith

goodo

canalsobereflectedfromtheinterioroftheinstrument,butitissimpletominimize

stisalsoimprovedbygoodcoatingduetothe

partialeliminationofinternalreflections.

Aclassiclens-coatingmaterialismagnesiumfluoride;itreducesreflectionsfrom5%

to1%.Modernlenscoatingsconsistofcomplexmulti-layersandreflectonly0.25%

orlesstoyieldanimagewithmaximumbrightnessandnaturalcolors.

[edit]Roofprismphasecorrectioncoating

Inbinocularswithroofprismsmultipleinternalreflectionsinaroofprismcausea

polarization-dependentphase-lagofthetransmittedlight,inamannersimilartoa

Fresnelrhomb.

Thelightpaththroughtheroofprismissplitintwopathsthatreflectoneithersideof

any

reflection,includingtotalinternalreflectioninsideaprism,unpolarizedlightbecomes

subsequentreflectionsthedirectionofthispolarization

vectorischangedbutitischangeddifferentlyforeachpathinamannersimilartoa

elightfollowingthetwopathsarerecombinedthe

lebetweenthetwo

polarizationvectorcalledthephaseshift,orthegeometricphase,ortheBerryphase.

Inaroofprismwithoutaphasecorrectingcoatinginterference不瘟不火 betweenthetwopaths

withdifferentgeometricphaseresultsinanvaryingintensitydistributionintheimage

reducingapparentcontrastandresolutioncomparedtoaporroprismerectingsystem.

ThiseffectcanbeseenintheelongationoftheAirydisk[6]inthesamedirectionas

thecrestoftheroof.

Theunwantedinterferenceeffectsaresuppressedbyvapourdepositingaspecial

dielectriccoatingknownasaphase-correctioncoatingorP-coatingontheroof

atingcorrectsforthedifferenceingeometricphase

betweenthetwopathssobothhaveeffectivelythesamephaseshiftandno

interferencedegradestheimage.

BinocularsusingeitheraSchmidt-PechanroofprismoraAbbe-Koenigroofprism

rismbinocularsdonotrecombinebeamsafter

followingtwopathswithdifferentphaseandsodonotbenefitfromaphasecoating.

[edit]Roofprismmetallicmirrorcoating

Mainarticle:Mirror

InbinocularsthatuseaSchmidt-Pechanroofprismsomesurfacesoftheroofprism

mustbemirrorcoatedforefficientreflectionsincethelightisincidentatoneofthe

glass-airboundariesatananglelessthanthecriticalanglesototalinternalreflection

llyan

aluminummirrorcoating(reflectivityof87%to93%)orsilvermirrorcoating

(reflectivityof95%to98%)isused.

Inolderbinoculardesignssilvermirrorcoatingswereusedbutthesecoatings

ummirror

coatingswereusedinlaterunsealeddesignsbecauseitdidnottarnisheventhoughit

binoculardesignsuseeitheraluminumor

isusedinmodernhigh-qualitydesignsasmodernbinocularsaresealed

andnitrogenorargonfilledsothesilvermirrorcoatingdoesn\'ttarnishinaninert

atmosphere.[7]

Porroprismbinocularsandroofprismbino过故人庄 孟浩然诗意 cularsusingtheAbbe-Koenigroofprism

donotusemirrorcoatingsbecausetheseprismsreflectwith100%reflectivityusing

totalinternalreflectionintheprism.

[edit]Roofprismdielectricmirrorcoating

Mainarticle:Dielectricmirror

AdielectriccoatingonaSchmidt-Pechanroofprismcausestheprismsurfacestoact

-metallicdielectricreflectivecoatingisformedfrom

severalmultilayersofalternatinghighandlowrefractiveindexmaterialsdepositedon

theroofprism游褒禅山记翻译一句一译 \'nglemultilayerreflectsanarrowbandof

lightfrequenciessoseveralmultilayers,eachtunedtoadifferentcolor,arerequiredto

lti-multilayercoatingincreasesreflectivityfromtheprism

-designeddielectriccoating

canprovideareflectivityofmorethan99%

reflectivityismuchimprovedcomparedtoeitheranaluminummirrorcoating(87%to

93%)orsilvermirrorcoating(95%to98%).

PorroprismbinocularsandroofprismbinocularsusingtheAbbe-Koenigroofprism

donotusedielectriccoatingsbecausetheseprismsreflectwithveryhighreflectivity

usingtotalinternalreflectionintheprismratherthanrequiringamirrorcoating.

[edit]Marketingtermsusedtodenotecoatings

Thepresenceofanycoatingsistypicallydenotedonbinocularsbythefollowing

terms:

coatedoptics:oneormoresurfacesareanti-reflectivecoatedwitha

single-layercoating.

fullycoated:allair-to-glasssurfacesareanti-reflectivecoatedwitha

clenses,however,ifused,maynotbecoated[citation

needed].

multi-coated:oneormoresurfaceshaveanti-reflectivemulti-layercoatings.

fullymulti-coated:allair-to-glasssurfacesareanti-reflectivemulti-layer

coated.

phase-coatedorP-coating:theroofprismhasaphase-correctingcoating

aluminum-coated:theroofprismmirrorsarecoatedwithanaluminumcoating.

Thedefaultifamirrorcoatingisn\'tmentioned.

silver-coated:theroofprismmirrorsarecoatedwithasilvercoating

dielectric-coated:theroofprismmirrorsarecoatedwithadielectriccoating

[edit]Mechanicaldesign

[edit]Focusingandadjustment

Binocularstobeusedtoviewobjectsthatarenotatafixeddistancemusthavea

ionally,twodifferentarrangementshavebeenusedto

larswith\"independentfocus\"requirethetwotelescopestobe

focusedindependentlybyadjustingeacheyepiece,therebychangingthedistance

larsdesignedforheavyfielduse,suchas

militaryapplications,egeneral

usersfinditmoreconvenienttofocusbothtubeswithoneadjustmentaction,asecond

typeofbinocularincorporates\"centralfocusing\",whichinvolvesrotationofacentral

tion,oneofthetwoeyepiecescanbefurtheradjustedto

compensatefordifferencesbetweentheviewer\'seyes(usuallybyrotatingthe

eyepieceinitsmount).Becausethefocalchangeeffectedbytheadjustableeyepiece

canbemeasuredinthecustomaryunitofrefractivepower,thediopter,theadjustable

eyepieceitselfisoftencalleda\"diopter.\"Oncethisadjustmenthasbeenmadefora

givenviewer,thebinocularscanberefocusedonanobjectatadifferentdistanceby

usingthefocusingwheeltomovebothtubestogetherwithouteyepiecereadjustment.

Binocularwithinternalelementsvisible

Therearealso\"focus-free\"or\"fixed-focus\"veadepthoffield

fromarelativelylargeclosestdistancetoinfinity,andperformexactlythesameasa

focusingmodelofthesameopticalquality(orlackofit)focusedonthemiddle

distance.

Zoombinoculars,whileinprincipleagoodidea,aregenerallyconsiderednotto

blemisthatitisveryd能把人读哭的情感电台文本 ifficulttocoordinatethe

emagnificationisnotperfectly

matched,theuser\'ustainedviewing,

rpertheopticsare,themoreprecise

matchingisneeded,sosuccessfulzoombinocularstendtobeofloweropticalquality.

Mostmodernbinocularshavehinged-telescopeconstructionthatenablesthedistance

betweeneyepiecestobeadjustedtoaccommodateviewerswithdifferenteye

justmentfeatureislackingonmanyolderbinoculars.

[edit]Imagestabilization

Shakecanbemuchreduced,andhighermagnificationsused,withbinocularsusing

ftheinstrumentwhichchangethepositionof

theimagemaybeheldsteadybypoweredgyroscopesorbypoweredmechanisms

drivenbygyroscopicorinertialdetectors,ormaybemountedinsuchawayasto

izationmaybeenabledor

echniquesallowbinocularsupto20tobe

hand-held,

aresomedisadvantages:theimagemaynotbequiteasgoodasthebestunstabilized

binocularswhentripod-mounted,stabilizedbinocularsalsotendtobemoreexpensive

andheavierthansimilarlyspecifiednon-stabilis云台二十八将唯一女将 edbinoculars.

[edit]Alignment

Well-collimatedbinoculars,whenviewedthroughhumaneyesandprocessedbya

humanbrain,shouldproduceasinglecircular,apparentlythree-dimensionalimage,

withnovisibleindicationthatoneisactuallyviewingtwodistinctimagesfrom

urefromtheidealwillcause,atbest,vague

discomfortandvisualfatigue,buttheperceivedfieldofviewwillbeclosetocircular

ematicconventionusedtorepresentaviewthroughbinocularsastwo

circlespartiallyoverlappinginafigure-of-eightshapeisnottruetolife.

Misalignmentisremediedbysmallm言不及义 ovementstotheprisms,oftenbyturningscrews

accessiblewithoutopeningthebinoculars,orbyadjustingthepositionofthe

entisusuallydoneby

aprofessionalalthoughinstructionsforcheckingbinocularsforcollimationerrorsand

forcollimatingthemcanbefoundontheInternet.

[edit]Applications

talkpagefordetails.(April

2009)

[edit]Generaluse

PeopleinOrchid,Floridausebinocularsforbirdwatching.

Hand-heldbinocularsrangefromsmall3x10Galileanoperaglasses,usedintheaters,

toglasseswith7to12diametersmagnificationand30to50mmobjectivesfortypical

rismmodelspredominatealthoughbirdwatchersandhunterstend

toprefer,andarepreparedtopayfor,thelighterbutmoreexpensiveroof-prism

models.

Manytouristattractionshaveinstalledpedestal-mounted,coin-operatedbinocularsto

nitedKingdom,20

penceoftengivesacoupleofminutesofoperation,andintheUnitedStates,oneor

twoquartersgivesbetweenone-and-a-halftotwo-and-a-halfminutes.

Coin-operatedbinocular

[edit]Military

andesignswerewidelyusedup

lars

constructedforgeneralmilitaryusetendtobemoreheavilyruggedizedthantheir

nerallyavoidmorefragilecenterfocusarrangementsin

favorofindependentfocus,whichalsomakesforeasier,moreeffective

etsinmilitarybinocularsmayhaveredundantaluminized

coatingsontheirprismsetstoguaranteetheydon’tlosetheirreflectivequalitiesif

rybinocularsoftheColdWareraweresometimesfittedwith

passivesensorsthatdetectedactiveIRemissions,whilemodernonesusuallyare

r,binocularsdesignedformilitary

usagemayincludeastadiametricreticleinoneocularinordertofacilitaterange

estimation.

Navalshipbinocular

There

heldmodelswillbe5to7butwithverylargeprismsetscombinedwitheyepieces

ticalcombinationpreventstheimage

vignettingorgoingdarkwhenthebinocularispitchingandvibratingrelativetothe

viewer\',high-magnificationmodelswithlargeobjectivesarealsousedin

fixedmountings.

Verylargebinocularnavalrangefinders(upto15metersseparationofthetwo

objectivelenses,weight10tons,forrangingWorldWarIInavalguntargets25km

away)havebeenused,althoughlate-20thcenturytechnologymadethisapplication

redundant.

[edit]Astronomical

Binocularsarewidelyusedbyamateurastronomers;theirwidefieldofviewmaking

themusefulforcometandsupernovaseeking(giantbinoculars)andgeneral

observation(portablebinoculars).Somebinocularsinthe70mmandlargerrange

remainusefulforterrestrialviewing;trueastronomicalbinoculardesigns(often90

mmandlarger)typicallydispensewithprismsforcorrectimageterrestrialviewingin

nocularsalsohaveremovableeyepieces

tovarymagnificationandaretypicallynotdesignedtobewaterprooforwithstand

roughfielduse.

Ceres,Neptune,Pallas,Titan,andtheGalileanmoonsofJupiterareinvisibletothe

ghvisibleunaidedin

pollution-freeskies,UranusandVestarequirebinocularsforeasydetection.1050

binocularsarelimitedtoanmagnitudeofmagnitude+10to+11dependingonsky

idslikeInteramnia,Davida,Europaand,

unlessunderexceptionalconditionsHygiea,aretoofainttobeseenwithcommonly

setoofainttobeseenwithmostbinocularsaretheplanetary

moonsexcepttheGalileansandTitan,

deepskyobjects,openclusterscanbemagnificent,suchasthebrightdoublecluster

(NGC869andNGC884)intheconstellationPerseus,andglobularclusters,suchas

M13inHercules,ebulae,M17inSagittariusandtheNorth

Americannebula(NGC7000)inCygnusarealsoreadilyviewed.

15x70binocular.

Ofparticularrelevanceforlow-lightandastronomicalviewingistheratiobetween

magnificationfacilitatesa

largerfieldofviewwhichisusefulinviewinglargedeepskyobjectssuchasthe

MilkyWay,nebula,andgalaxies,thoughthelargeexitpupilmeanssomeofthe

geexitpupilwillalsoimagethenightskybackground,

effectivelydecreasingcontrast,makingthedetectionoffaintobjectsmoredifficult

larsgeared

towardsastronomicalusesprovidethemostsatisfyingviewswithlargeraperture

objectives(inthe70mmor80mmrange).Astronomybinocularstypicallyhave

r,manyoftheobjectsintheMessier

Catalogandotherobjectsofeighthmagnitudeandbrighterarereadilyviewedin

hand-heldbinocularsinthe35to40mmrange,suchasarefoundinmanyhouseholds

forbirding,hunting,gerbinocularobjectivesare

preferredforastronomybecausethediameteroftheobjectivelensregulatesthetotal

amountoflightcaptured,andthereforedeterminesthefainteststarthatcanbe

heirhighmagnificationandheavyweight,thesebinocularsusually

ficationoften(10x)is

usuallyconsideredthemostthatcanbeheldcomfortablysteadywithoutatripodor

othermount.

Muchlargerbinocularshavebeenmadebyamateurtelescopemakers,essentially

usingtworefractingorreflectingastronomicaltelescopes,

largeprofessionalinstrument,althoughnotonethatwouldnormallybecalled

binoculars,istheLargeBinocularTelescopeinArizona,USA,whichproducedits

\"FirstLight\"imageonOctober26,comprisestwo8-meterreflector

bviouslynotintendedtobeheldtotheeyesofaviewer,ituses

twotelescopestoviewthesameobject,givinghigherresolvingpowerthanasingle

instrumentofthesamelight-gatheringpower,andallowinginterferometricuse.

[edit]Manufacturers

inalphabeticalorder:

Bausch&Lomb(USA)–hasnotmadebinocularssince1976,whenthey

licensedtheirnametoBushnell,Inc.,whomadebinocularsundertheBausch&

Lombnameuntilthelicenseexpired,andwasnotrenewed,in2005.

Brunton,Inc.(USA)

BushnellCorporation(USA);AlsosellsOEMproductsmanufacturedbythe

n.

CanonInc.(Japan)–:porrovariants?

Celestron

Fujinon(Japan)–FMTSX,FMTSX-2,MTSXseries:porro.

LeicaCamera(Germany)–Ultravid,Duovid,Geovid:allareroofprism.

Leupold&Stevens,Inc.(USA).AlsosellsOEMproductsmanufacturedby

n.

Minox

NikonCorporation(Japan)–EDGSeries,HighGradeseries,Monarchseries,

RAII,Spotterseries:roofprism;Prostarseries,SuperiorEseries,Eseries,Action

EXseries:porro.

PentaxCorporation(Japan)–DCFED/SP/XPseries:roofprism;UCFseries:

invertedporro;PCFV/WP/XCFseries:porro.

SwarovskiOptik[8]

Vixen(telescopes)(Japan)–Apex/ApexPro:roofprism;Ultima:

n.

VortexOptics(USA)

Zeiss(Germany)–FL,Victory,Conquest:roofprism;750BGAT/Tporro,

1560BGA/Tporro,discontinued.