CCD camera

Basicinformation

Workingmethod

VariousCCDcameras(15photos)

TheimageofthesubjectpassesthroughthelensFocusingontheCCDchip,theCCDaccumulatesacorrespondingproportionofelectricchargeaccordingtotheintensityofthelight.Theelectricchargeaccumulatedbyeachpixelmovesoutpointbypointunderthecontrolofthevideotiming,andformsavideosignaloutputafterfilteringandamplifying.ThevideosignalisconnectedtothevideoinputterminalofthemonitororTVtoseethesamevideoimageastheoriginalimage.Itisasemiconductorimagingdevice.InordertosimplifythepowersupplyoftheCCDcamera,generallyonlyonepowersupply(12V)isinputfromtheoutside,andthepowersupplyofvariousvoltagevalues​​inthemachineisobtainedbypowerconversion.

Choiceofresolution

Theindexforevaluatingcameraresolutionishorizontalresolution,anditsunitislinepairs,thatis,thenumberofblackandwhitelinepairsthatcanbedistinguishedafterimaging.Theresolutionofcommonlyusedblackandwhitecamerasisgenerally380-600,andthecoloris380-480.Thelargerthevalue,theclearertheimage.Ingeneralsurveillancesituations,ablack-and-whitecamerawithabout400linescanmeettherequirements.Forspecialoccasionssuchasmedicaltreatmentandimageprocessing,a600-linecameracanobtainclearerimages.

Imagingsensitivity

Usuallytheminimumenvironmentalilluminationrequirementsareusedtoindicatethecamerasensitivity.Thesensitivityofablackandwhitecameraisabout0.02-0.5Lux(lux),andacolorcameraismostlyabove1Lux.The0.1Luxcameraisusedforordinarysurveillanceoccasions;whenusedatnightorwhentheambientlightisweak,itisrecommendedtousea0.02Luxcamera.Whenusedwithnear-infraredlights,low-illuminancecamerasmustalsobeused.

Inaddition,thesensitivityofthecameraisalsorelatedtothelens,0.97Lux/F0.75isequivalentto2.5Lux/F1.2isequivalentto3.4Lux/F1.

Referenceenvironmentalilluminance:100000Luxinsummersun,10000Luxoutdoorsincloudydays,1000LuxinTVstudio,300Luxfrom60Wdesklamp60cmdesktop,100Luxindoorfluorescentlamp,10Luxindooratdusk,10-15Luxcandlelightat20cm,nightStreetlight0.1Lux.

Electronicshutter

Thetimeoftheelectronicshutterisbetween1/50-1/100000seconds.Theelectronicshutterofthecameraisgenerallysettoautomaticelectronicshuttermode,whichcanbeadjustedaccordingtothebrightnessoftheenvironmentAutomaticallyadjusttheshuttertimetogetaclearimage.Somecamerasallowuserstomanuallyadjusttheshuttertimetosuitsomespecialapplications.

Externalsynchronizationandexternaltriggering

CCDcamera(18photos)

ExternalsynchronizationreferstotheuseofthesamesynchronizationsignalbetweendifferentvideodevicesToensurethesynchronizationofvideosignals,itcanensurethatthevideosignalsoutputbydifferentdeviceshavethesameframeandlinestartandendtime.Inordertoachieveexternalsynchronization,itisnecessarytoinputacompositesyncsignal(C-sync)orcompositevideosignaltothecamera.Externalsynchronizationdoesnotguaranteethattheuserwillgetacompleteandcontinuousframeofimagefromthespecifiedmoment.Torealizethisfunction,somespecialcameraswithexternaltriggerfunctionmustbeused.

TheCCDdeviceismadeofsiliconmaterial,whichismoresensitivetonear-infrared,andthespectralresponsecanbeextendedtoabout1.0um.Itsresponsepeakisgreenlight(550nm),distributioncurve.Whenconcealedsurveillanceatnight,itcanbeilluminatedbynear-infraredlights,sothatthehumaneyecan'tseetheenvironment,butitcanbeclearlyimagedonthemonitor.SincethesurfaceoftheCCDsensorhasatransparentelectrodethatabsorbsultraviolet,theCCDisnotsensitivetoultraviolet.Therearered,green,andbluefilterstripsontheimagingunitofthecolorcamera,sothecolorcameraisnotsensitivetoinfraredandultraviolet.

ThesizeoftheCCDchip

TheimagingsizeoftheCCDisusually1/2",1/3",etc.Thesmallertheimagingsize,thevolumeofthecameracanbemadesmaller.Underthesameopticallens,thelargertheimagingsize,thelargerthefieldofview.ChipspecificationsImagingareasize(widthXheight)Diagonal1/26.4x4.8mm8mm1/34.8x3.6mm6mmCameralensselectionguideHowtochoosethecorrectcameralensintheTVmonitoringsystemaccordingtothemonitoringenvironmentonsiteItisveryimportant,becauseitdirectlyaffectswhethertheeffectofthemonitoredsurfacepictureseenontheendmonitorofthesystemafterthesystemiscomposedcanmeetthedesignrequirementsofthesystem(intermsofscreenrangeorimagedetails),soitiscorrectThechoiceofcameralenscanmakethesystemgettheoptimaldesignandobtaingoodsurveillanceeffect.

Lensselection

Cameralensescanbedividedintomanualirislensandautomaticirislensintermsofaperture,andcanbedividedintotwotypes,fixedfocuslensandzoomlensintermsoffocallength.kind.Nowlet'stalkabouthowtochoosethecameralenscorrectlyaccordingtothedifferentuseenvironment.

1,manual,automaticirislensoptions

manual,automaticirislensThechoicedependsonwhethertheilluminanceoftheuseenvironmentisconstant.Inthecaseofconstantenvironmentalilluminance,suchasintheelevatorcar,enclosedcorridors,androomswithoutdirectsunlight,manualirislenscanbeselected,sothatitcanbeadjustedatonetimeaccordingtotheactualilluminanceoftheenvironmentduringtheinitialinstallationanddebuggingofthesystemTheaperturesizeofthelensissufficienttoobtainasatisfactorybrightnesspicture.Forsituationswheretheambientilluminancechangesfrequently,suchashalls,windows,andlobbieswheretheilluminancechangesgreatlywiththetimeofdaylight,anautomaticirislensisrequired(mustbeequippedwithacamerawithanautomaticirislenssocket),sothatyoucanRealizetheautomaticadjustmentofthescreenbrightness,andobtainagoodandrelativelyconstantbrightnessmonitoringscreen.ThecontrolsignalfortheautomaticirislenscanbedividedintoDCandVIDEOcontrol,namelyDCvoltagecontrolandvideosignalcontrol.Thisisintheselectionofthetypeofautomaticirislens,theconnectionmethodofthecamera'sautomaticirislenssocket,andtheselectionofthedrivemodeswitchoftheautomaticirislens.Payattentiontothecoordinationofthethree.

2.Thechoiceoffixedfocusandzoomlens

ThechoiceoffixedfocusandzoomlensdependsonthesizeofthemonitoredscenerangeandtherequiredMonitortheclarityofthescenescreen.Lensspecifications(lensspecificationsaregenerallydividedinto1/3”,1/2”and2/3”,etc.)Undercertaincircumstances,therelationshipbetweenthelensfocallengthandthelensfieldofviewangleis:thelongerthelensfocallength,thelens’sfieldofviewThesmallertheangle;inthecaseofacertainfocallengthofthelens,therelationshipbetweenthelensspecificationandthelensfieldofviewangleis:thelargerthelensspecification,thelargerthefieldofviewangleofthelens.Sofromtheaboverelationship,itcanbeseenthatthelensobjectdistanceisfixedInthecaseof,asthefocallengthofthelensbecomeslarger,thescreenrangeofthemonitoredsceneseenonthemonitorattheendofthesystembecomessmaller,butthescreendetailsbecomeclearerandclearer;andasthelensspecificationincreases,Thescreenrangeofthemonitoredsceneseenonthemonitorattheendofthesystemincreases,butthedetailsofthescreenaregettingblurred.Underthepremiseofcertainlensspecificationsandlensfocallength,thefieldofviewoftheCS-mountlenswillbelargerthanCThefieldofviewofthetypeinterfacelens.Commonlyusedlensmodelsare4mm,8mm,12mm,16mm.

Thefieldofviewofthelenscanbedividedintothehorizontalfieldofviewoftheimageandtheverticalfieldofviewoftheimage,andtheimageishorizontal.Thefieldofviewisgreaterthantheverticalfieldofviewoftheimage.Usually,thefieldofviewwetalkaboutgenerallyreferstothehorizontalfieldofviewofthelens.

Inasmallmonitoredenvironmentsuchasanelevatorcar,itissmallAllroomsshoulduseshortfocallengthwide-angleorultra-wide-anglefixed-focuslenses.Ifthelenssizeis1/2″,CStypeinterface,thefocallengthofthelensis3.6mmor2.6mm,thefieldofviewoftheselensesisnotlessthan99°or127°,forthecamerainanarrowspace,whenthegeneralelevationisabout2.5m,thefieldofviewofthelensissufficienttocovertheentireclose-rangeandnarrowspacetobemonitored.AmanualzoomlenssuchasNissanComputarT2Z2814CS-2lenscanalsobeselectedaccordingtotheactualsituationonsite.Thislensisa1/3"CS-typemanualirislenswithafocallengthof2timesadjustable(manualfocusing).Thefocusingrangeis2.8～6.0mm,therangeoffieldofviewangleis96°～47.2°.Thiskindoflensisverysuitableforuseinasmallmonitoredenvironment.Itcanbeusedconvenientlyandflexiblyaccordingtoactualneedstorealizethe"point"ofthemonitoredscene.Or"surface"monitoringeffect.

Forgeneralzoom(times)lens,sinceitsminimumfocallengthisusuallyabout6.0mm,themaximumfieldofviewofitszoom(times)lensis45°Ontheleftandright,ifthiskindoflensisusedinsuchanarrowmonitoredenvironment,itsmonitoringblindanglewillinevitablyincrease.Althoughthefront-endpan/tiltcanbeoperatedandcontrolledtoreducethismonitoringblindangle,thiswilldefinitelyincreasethesystem.Theengineeringcost(thesystemneedstoaddfront-enddecoder,PTZ,protectivecover,etc.),andthecomplexityofsystemcontrol,sointhisenvironment,zoom(times)lensshouldnotbeused.

Inthemonitoredenvironment,firstly,accordingtotheopennessofthemonitoredenvironment,theuserrequirestheclarityofthemonitoredscenepictureseenonthemonitorattheendofthesystem,andthestraightlinebetweenthecenterpointofthemonitoredsceneandthecameralensThedistanceisthereferencebasis.Underthepremisethatthestraightlinedistanceisfixedandtheentiremonitoredsceneiscovered,thelongfocallengthlensshouldbeconsideredasfaraspossible,sothataclearanddetailedsceneofthemonitoredscenecanbeobtainedontheendmonitorofthesystem.

Inthisenvironment,zoom(times)lens(electricthree-variablelens)canalsobeconsidered,whichcanbedeterminedaccordingtothedesignrequirementsofthesystemandtheperformance-priceratioofthesystem,andshouldalsobeconsideredwhenselectingTwopoints:

⑴Whenadjustedtotheshortestfocallength(viewingthepanorama),itshouldbeabletomeettherequirementsofcoveringthemainmonitoredscenes;

⑵Whenadjustingtothelongestfocallength(viewingtheDetails)shouldbeabletomeettherequirementsforobservingthedetailsofthescenebeingmonitored.Generally,inindoorwarehouses,workshops,factoriesandotherenvironments,6xor10xlensescangenerallybeusedtomeettherequirements,whileinoutdoorwarehousesanddocksInenvironmentssuchassquares,stations,etc.,10x,16x,or20xlensescanbeselectedaccordingtoactualrequirements.(Generally,thelargerthelens,thehighertheprice.Itcanbeappropriateunderthepremiseofcomprehensiveconsiderationofthesystemcost.Useahigh-powerzoomlens).

3.Thetheoreticalcalculationofthecorrectselectionofthelensfocallength

Theangleofviewofthelensforcapturingthesceneisanextremelyimportantparameter.Thefieldofviewofthelenschangeswiththefocallengthofthelensandthesizeofthecamera(thechangerelationshipisasdescribedabove),andthefocallengthofthecoveringlenscanbecalculatedbythefollowingformula:⑴f=u*D/U;⑵f=h*D/Hf:Thefocallengthofthelens,U:theactualheightofthescene,H:theactualwidthofthescene,D:themeasureddistancefromthelenstothescene,u:theheightoftheimage,h:thewidthoftheimage.Forexample:when1/2″isselectedWhenthelensisused,theimagesizeisu=4.8mm,h=6.4mm,thedistancefromthelenstothesceneD=3500mm,theactualheightofthesceneisU=2500mm(theactualwidthofthescenecanbecalculatedbythefollowingformulaH=1.333·U,thisrelationshipDeterminedbythecameraviewfinderCCDfilm).Substitutingtheaboveparametersintotheformula(1),f=4.8·3500/2500=6.72mm,soa6mmfixedfocuslenscanbeused.

Principleofcomposition

Circuitcomposition

ThecircuitconstitutingtheIT-CCDmonochromecameraconsistsofIT-CCDcameradevice,timingpulsegeneratoranddrivingcircuit,andvideoSamplingandholdingcircuit,videoprocessingcircuit,synchronizationsignalgenerator,powerconversioncircuitandothercomponents.

Workingprinciple

⑴CCDcameradevice:Itsfunctionistoperformphotoelectricconversionandoutputvideosignal

⑵Timingpulsegeneratoranddrivingcircuit:itsfunctionistogenerateCCDcameradeviceperformsvariouspulsesignalsrequiredforphotoelectricconversion,chargestorage,chargetransferandsignaloutput,andimplementsamplifyingoutput

⑶Videosamplingandholdingcircuit:itsfunctionistoeliminatetheoutputofCCDInthevideosignal(thissignalisdiscreteintimeandcontinuousinamplitude),variousundesirablesignalsgeneratedbythetransferofsignalcharge.Afterprocessingbythiscircuit,thevideosignalbecomesadigitalvideosignal.

⑷Videoprocessingcircuit:Thiscircuithasexactlythesamecharacteristicsasthevideotubecameracircuit.Thecircuitsinvolvedincludeclampamplifier(CLAMPERAMP),Ycorrection(YCORRECT),andwhiteelectricity.Flatcutting(whiteclip,WHTCLIP),blankingmax(BLKMAX),blackandwhitelevelcontrol(PEDCONT),synchronousmixing(SYNC),outputdriver(outputdriver)andothercircuits.ThevideosignalisprocessedbythevideoprocessingcircuittoformastandardfullTVsignal.

⑸Synchronizationsignalgenerator:Thispartofthecircuitisbasicallythesameastheprincipleofthesynchronizationsignalgeneratorinthecameratubecamera.Itmainlygeneratesthepulsesignalsrequiredbythevideoprocessingcircuit.Theyarecompositeblankingpulses(BLK),compositesyncpulse(SYNC),horizontaldrivesignalHD,interlacedpulse(O/E).ButbecausetheCCDcameradoesnothaveascanningcircuit,itdoesnotneedadrivingpulseforthescanningcircuit.

⑹Powerconversioncircuit:InordertosimplifythepowersupplyoftheCCDcamera,generallyonlyonepowersupply(12V)isinputfromtheoutside,andthepowersupplyofvariousvoltagevalues​​inthemachineisobtainedbypowerconversion.

Performanceindicators

Thecamerahasmanyfunctions,suchasautomaticwhitebalanceadjustment,automaticgainadjustment,electronicshutter,backlightcompensation,multiplesynchronizationmethods,Y/Cseparateoutput,andsoon.However,themostimportantindicatorsforinvestigatingcameragradesarehorizontalclarity,minimumillumination(sensitivity)andsignal-to-noiseratio.

Sharpness

Thenumberofsharpnessisanimportantparametertomeasurethequalityofthecamera.ItreferstotheThemaximumnumberoflinesthatcanbeseenonthecamerawithhighresolution.Whenthisnumberoflinesisexceeded,onlyagraypatchcanbeseenonthescreenandblackandwhitelinescannolongerbedistinguished.

Theresolutionofindustrialsurveillancecamerasisusuallybetween380and460lines,andtheresolutionofbroadcastcamerascanreachabout700lines.Thedefinitionisdeterminedbythenumberofpixelsoftheimagingdevice.Obviously,themorepixelsoftheimagingdevice,theclearertheimageobtained,andviceversa.Thehigherthedefinition,thehigherthecameragrade,andviceversa.

MinimumIllumination

MinimumIlluminanceisthelowestilluminancewhenthebrightnessofthesubjectislowtoacertainlevelandthevideosignalleveloutputbythecameraislowtoacertainvalueThebrightnessvalueofthescene.Generally,theminimumilluminanceofacolorcamerais2～3LUX,andthemeasurementofilluminanceisbasedonacertainlensaperturecoefficient.Therefore,youcan’tjustlookattheminimumilluminanceindicatedinthecameramanual.Itshouldbebasedonthecamera’silluminancevalueunderthesameaperturecoefficient.size.Thelowertheminimumillumination,thehigherthecameragrade.Comparedwithcolorcameras,black-and-whitecamerasareonlysensitivetotheintensity(brightness)signaloflightbecausetheydonothavechromaticityprocessing.Therefore,theilluminanceofblack-and-whitecamerasislowerthanthatofcolorcameras.Generally,itcanachieve0.1LUXatF1.4.,Asforthelow-lightcamera,itisevenlower.Fortheknowledgeoftheaperturefactor,pleaserefertothelenssection.

Thenominalvalueofthevideosignalis1Vp-p,thestandardvalueis0.7Vp-p,andthevideosignalvalueatthelowestilluminanceis1/3to1/2ofthestandardplant.Therefore,theimageofthecameraatthelowestilluminancewillneverbe"likedaylight."Inaddition,theimageclarityproducedbythecameraatthelowestilluminanceismeasuredwithaTVsignaltestcard.Theblackandwhitestripesrequiretheblackreflectivitytobecloseto0%andthewhitereflectivitytobegreaterthan89.9%.However,wesometimesdonothavesuchconditionswhenobservingonthespot.Forexample,thereflectivityofleavesandgrassisverylow,andthecontrastisverysmall,soitisnoteasytoobtainaclearimage.Therefore,inactualuse,thenominalminimumilluminanceofthecameracannotbeusedasthestandardformeasuringtheon-siteenvironmentalilluminance.

Signal-to-noiseratio

Thesignal-to-noiseratioisalsoanimportantperformanceindexofthecamera.Whenthecameracapturesabrightscene,themonitordisplayisusuallybrighter,anditisdifficultfortheobservertoseetheinterferenceandnoiseintheimage;whenthecameracapturesadarkscene,themonitordisplayisrelativelydim,andtheobserverItiseasytoseethesnowflake-likenoiseinthepicture.Thestrengthofinterferencenoise(thatis,thedegreeofinfluenceofinterferencenoiseonthepicture)isdirectlyrelatedtothequalityofthecamera'ssignal-to-noiseratio,thatis,thehigherthecamera'ssignal-to-noiseratio,thesmallertheinfluenceofinterferencenoiseonthepicture.

Theso-called"signal-to-noiseratio"referstotheratioofsignalvoltagetonoisevoltage,usuallyrepresentedbythesymbolS/N.Ingeneral,thesignalvoltageismuchhigherthanthenoisevoltage,andtheratioisverylarge.Therefore,theactualcalculationofthecamerasignal-to-noiseratioisusuallybasedontheratioofthemeansquaresignalvoltagetothemeansquarenoisevoltage.Thenumberismultipliedbyafactorof20,andtheunitisexpressedindB.

Generally,thesignal-to-noiseratiovaluegivenbythecameraisthevaluewhentheAGC(automaticgaincontrol)isturnedoff,becausewhentheAGCisturnedon,thesmallsignalwillbeboosted,sothatthenoiselevelisalsocorrespondingimprove.ThetypicalvalueofCCDcameraSNRisgenerally45dB~55dB.Whenmeasuringthesignal-to-noiseratioparameters,avideocluttermetershouldbeusedtoconnectdirectlytothevideooutputterminalofthecamera.

AutomaticGainControl

AGC-theabbreviationofAutomaticGainControl.AllcamerashaveavideoamplifierthatamplifiesthesignalfromtheCCDtoausablelevel.Theamountofamplificationisthegain,whichisequivalenttoahighersensitivity,whichcanmakeitsensitiveinlowlight,butinabrightlightenvironmentTheamplifierwillbeoverloaded,distortingthevideosignal.Forthisreason,itisnecessarytousethecamera'sautomaticgaincontrol(AGC)circuittodetectthelevelofthevideosignal,andtoswitchtheAGCinatimelymanner,sothatthecameracanworkinalargerlightrange,whichisthedynamicrange,thatis,atlowThesensitivityofthecameraisautomaticallyincreasedduringillumination,therebyincreasingtheintensityoftheimagesignaltoobtainaclearimage.CameraswithAGCfunctionwillhavehighersensitivityatlowillumination,butthenoisewillbemoreobviousatthistime.Thisisbecausethesignalandnoiseareamplifiedatthesametime.

BacklightCompensation

BLC-theabbreviationofBackLightCompesation,alsoknownasBacklightCompensationorBacklightCompensation,itcaneffectivelycompensateforthedarkdefectsofthemainbodyofthepicturewhenthecameraisshootinginabacklitenvironment.Usually,thecamera'sAGCworkingpointisdeterminedbyaveragingthecontentoftheentirefieldofview,butifthefieldofviewcontainsaverybrightbackgroundareaandaverydarkforegroundtarget,theAGCworkdeterminedatthistimeThepointmaynotbesuitablefortheforegroundtarget,andthebackgroundlightcompensationmayimprovethedisplayconditionoftheforegroundtarget.

Whenthebacklightcompensationfunctionisintroduced,thecameraonlydetectsasub-areaof​​theentirefieldofview(suchasthecentralareafromthe80thlinetothe200thline),andcalculatestheaveragesignallevelofthisarea.DeterminetheoperatingpointoftheAGCcircuit.Sincetheaveragelevelofthesub-regionisverylow,theAGCamplifierwillhaveahighergain,whichwillincreasetheamplitudeoftheoutputvideosignal,therebymakingthemainpictureonthemonitorclearer.Atthistime,thebackgroundpicturewillbebrighter,butthesubjectivebrightnessdifferencebetweenitandthemainpicturewillbegreatlyreduced,andthevisibilityoftheentirefieldofviewwillbeimproved.

Whenthebackgroundlightcompensationisturnedon,thecameraonlyaveragesasub-regionoftheentirefieldofviewtodetermineitsAGCoperatingpoint.Atthistime,iftheforegroundtargetislocatedinthissub-region,theforegroundThevisibilityoftargetsisexpectedtoimprove.

ElectronicShutter(ES)

ThefullEnglishnameofElectronicShutterisElectronicShutter,whichisatermthatcomparesthemechanicalshutterfunctionofacamera,whichisequivalenttocontrollingtheexposuretimeofaCCDimagesensor.SincetheessenceofCCDlight-sensingistheaccumulationofsignalcharge,thelongerthelight-sensingtime,thelongerthesignalchargeaccumulationtime,andthegreatertheamplitudeoftheoutputsignalcurrent.Byadjustingtheaccumulationtimeofthephotogeneratedsignalcharge(thatis,adjustingthewidthoftheclockpulse),thefunctionofcontrollingtheCCDlight-sensingtimecanberealized.

WhiteBalance(WB)

WhiteBalance(WhiteBalance),onlyusedforcolorcameras,itspurposeistorealizethecameraimagecanaccuratelyreflectthesituationofthescene,thereismanualTherearetwowaysofwhitebalanceandautomaticwhitebalance.

Automaticwhitebalance(AWB,AutomaticWhiteBalance)isdividedintocontinuouswhitebalanceandautomaticcontrolwhitebalance.

ContinuouswhitebalanceisalsocalledAutomaticTrackingWhitebalance(ATW),whichiscontinuouslyadjustedasthecolortemperatureofthescenechanges,andtherangeis2800~6000K.Thismethodismostsuitableforoccasionswherethecolortemperatureofthesceneisconstantlychangingduringshooting,tomakethecolorappearnatural,butwhenthereislittleornowhiteinthescene,suchasthesceneismostlybluesky,whitecloudsorsunsetandotherhighcolortemperatureobjectsandWhenthesceneisdark,continuouswhitebalancecannotproducethebestcoloreffect.

AutomaticWhitebalanceControl(AWC),youneedtofirstaimthecameraatawhitereferencetargetsuchasawhitewall,whitepaper,etc.,andthenchangethemenuorswitchsettingsfrommanualtoAutomode,stayatthispositionforafewsecondsoruntiltheimageappearswhite.Afterthewhitebalanceisexecuted,turntheautomodeswitchbacktothemanualpositiontolockthewhitebalancesetting.Atthistime,thewhitebalancesettingwillremaininthecameraInthememoryofthecamera,therangeis2300~10000Kuntiltheexecutionischangedagain.Duringthisperiod,thesettingwillnotbelostevenifthecameraispoweredoff.Itisthemostaccurateandreliablewaytosetthewhitebalancebybutton,whichissuitableformostapplications.

ManualwhitebalanceTurnofftheautomaticwhitebalance,andmanuallyadjusttheredorblueadjustmentdevicetochangetheredorbluecondition.Generally,thereareupto107adjustablelevels,suchasincreasingordecreasingredbyoneleveleach,Increaseordecreasebluebyoneleveleach.

Inaddition,somecamerashavecommandstofixthewhitebalanceat3200K(incandescentlamplevel)and5500K(daylightlevel).

Synchronizationmethod

Thecamerasynchronizationmethodsgenerallyincludeinternalsynchronization,powersynchronizationandexternalsynchronization.

Internalsynchronization(INT)istousethecrystaloscillatorcircuitinsidethecameratogenerateasynchronizationsignaltocompletetheoperation.Powersynchronization(LL,LineLocked),alsoknownaslinearlockingorlinelocking,usesthecamera'sACpowersupplytocompletetheverticaldrivesynchronization,thatis,thecameraissynchronizedwiththepowerzeroline.

Externalsynchronization(EXT)usesasynchronizationsignalgeneratedbyanexternalsynchronizationsignalgeneratortosendtothecamera'sexternalsynchronizationinputtoachievesynchronization.Thesynchronizationsignalcanbeacolorcompositevideoorblackburstsignal(VBS),ablackandwhitecompositevideooracompositesynchronizationsignal(VS),oritcanbeamultiplexedverticaldrivesignal(VD2)andcompositevideooutputsignalofanexternaldevicesuchasamatrix.