Ubuchwepheshe Bokukhanyisa I-IR Kumakhamera E-CCTV
Eminyakeni yamuva nje, amakhamera e-CCTV awasathembeli kuphela ekukhanyeni okuvamile ukuze athwebule izithombe. Isidingo sokuqapha amahora angama-24—kungaba sekhaya, ehhovisi, endaweni yokugcina impahla, esakhiweni somphakathi, noma endaweni yezimboni—siholele ekuthuthukisweni kobuchwepheshe bokukhanyisa nge-infrared (IR) ukuze amakhamera akwazi "ukubona" ezimweni zokukhanya okuphansi noma ngisho nasebumnyameni obuphelele. Ubuchwepheshe bokukhanyisa nge-IR kumakhamera e-CCTV sebube ngenye yezici ezibaluleke kakhulu ezinhlelweni zokuphepha zanamuhla ngoba buvumela ukuqapha ebusuku ngaphandle kwesidingo sezibani ezikhanyayo nezikhanyayo. Lesi sihloko sixoxa ngendlela esebenza ngayo, izingxenye zayo, izinhlobo, izinzuzo kanye nokungalungi, kanye namathiphu okukhetha nokufaka i-CCTV ene-IR.
Kuyini ukukhanya kwe-IR ku-CCTV?
Ukukhanya kwe-IR uhlelo lokukhanyisa olusebenzisa amaza kagesi e-infrared, awela ngaphandle kobubanzi obubonakalayo bokubona komuntu. Lokhu kusho ukuthi ukukhanya kwe-IR ngokuvamile akubonakali emehlweni omuntu, kodwa kungatholwa yinzwa yekhamera. Kumakhamera e-CCTV, i-IR ivame ukukhiqizwa ngama-LED e-infrared atholakala eduze kwelensi (indandatho ye-IR) noma kumojuli enikezelwe. Uma kumnyama, ikhamera isebenzisa ama-LED e-IR ukuze ikhanyise indawo ngokukhanya kwe-infrared, iqinisekise ukuthi izinto zihlala zibonakala ku-footage.
Umphumela ojwayelekile isithombe esimnyama nomhlophe (esinombala ofanayo). Lokhu kwenzeka ngoba kwimodi yasebusuku, ikhamera ivame ukukhubaza izihlungi ezithile bese ishintshela kusethingi yesensa ezwela kakhulu ku-IR.
Indlela ubuchwepheshe be-IR obusebenza ngayo: kusukela emini kuya ebusuku
Ukuze ikhamera ikwazi ukuzivumelanisa nezimo zokukhanya nezimnyama, kunezindlela ezivamile ezisetshenziswayo:
1. Inzwa yokukhanya (i-LDR/i-photocell)
Ikhamera inenzwa elinganisa amazinga okukhanya okuzungezile. Uma ukukhanya kwehla ngaphansi komkhawulo othile, ikhamera ishintsha ngokuzenzakalelayo amamodi.
2. Isihlungi esinqunyiwe nge-IR (ICR – Ukususwa Kwesihlungi Esinqunyiwe Nge-Infrared)
Emini, amakhamera asebenzisa isihlungi esinqunyiwe nge-IR ukuhlunga ukukhanya kwe-infrared ukuqinisekisa imibala ebukeka njengeyemvelo. Ngaphandle kokuhlunga nge-IR, imibala ivame "ukungasebenzi" noma ibonakale inganembile.
Ebusuku, isihlungi esinqunyiwe se-IR siyaphakanyiswa (i-mechanical ICR) noma singasebenzi (kweminye imiklamo) ukuvumela inzwa ukuthi ibambe ukukhanya kwe-IR.
3. I-IR LED iyakhanya
Uma imodi yasebusuku isebenza, i-IR LED iyakhanyisa futhi ikhiphe ukukhanya kwe-infrared endaweni ezungezile. Ukukhanya kwe-IR okubonakalayo okuvela ezintweni kungena kabusha kulensi bese kubanjwa yinzwa.
4. Ukucutshungulwa kwesithombe (i-ISP)
Iprosesa Yesiginali Yesithombe (i-ISP) engaphakathi kwekhamera icubungula isignali evela ku-sensor. Ngenxa yokuthi i-IR ayinalo ulwazi lombala olufanayo nokukhanya okubonakalayo, amakhamera ngokuvamile abonisa izithombe ezimnyama nezimhlophe ezinomehluko olungisiwe.
Ngale ndlela, ikhamera ingagcina ukubonakala ebusuku ngaphandle kokukhanya okumhlophe okwengeziwe.
Ubude be-IR: 850 nm vs 940 nm
Ku-CCTV, izinhlobo ezimbili ezivame kakhulu zamaza e-IR yi-850 nm kanye ne-940 nm.
– IR 850 nm
Zivame ukusetshenziswa kakhulu ngoba "zikhanya kakhulu" kakhulu kuma-sensor ekhamera. Ibanga livame ukuba ngcono, futhi izithombe zivame ukuba sobala. Kodwa-ke, ama-LED angu-850nm avame ukukhipha ukukhanya okubomvu okuncane okungabonakala uma ubheka ikhamera ngqo ebusuku.
– IR 940 nm
Ngokuvamile ibizwa ngokuthi "akukho ukukhanya" noma "i-IR engabonakali" ngoba kunzima kakhulu ukuyibona ngeso lomuntu. Ifaneleka ezindaweni lapho ukucasha kubalulekile khona, njengokuqapha lapho kungafunwa khona ukunakwa. Inkinga: izinzwa zekhamera ngokuvamile azizweli kakhulu ku-940 nm kunaku-850 nm, okungabangela ububanzi obufushane obusebenzayo noma kudinge i-LED enamandla kakhulu.
Ukukhetha okungu-850 nm noma okungu-940 nm kufanele kulungiswe ngokwezidingo zakho: kungakhathaliseki ukuthi ubeka phambili ibanga nemininingwane, noma ubeke phambili "ukukhanya" okubomvu okuncane.
Izingxenye eziyinhloko zesistimu ye-IR ku-CCTV
Ubuchwepheshe be-IR abugcini nje ngama-LED. Izingxenye eziningana ziyathintana:
1. I-IR LED kanye nomshayeli
I-LED ingumthombo we-IR, kuyilapho umshayeli elawula ugesi ukuqinisekisa ukuzinza, ukugcinwa kokushisa, kanye nokuphila isikhathi eside. Ikhwalithi yomshayeli ithinta ukuzinza kokukhanya kanye nokuqina kwe-LED.
2. Ilensi kanye nomklamo we-optical
I-engeli ye-IR LED beam kumele ivumelane ne-engeli yokubuka yelensi yekhamera. Uma ingavumelani, ukukhanya kanye nezindawo zokubamba zekhamera ngeke zilingane—isibonelo, isikhungo sizokhanya kodwa imiphetho izoba mnyama.
3. Inzwa yekhamera (i-CMOS)
Ukuzwela kwezinzwa ku-IR kuyahlukahluka. Izinzwa ezingcono zivame ukuletha umsindo ophansi kanye nemininingwane ebukhali ezimweni zokukhanya okuphansi.
4. Isihlungi somshini esinqunyiwe nge-IR
Indlela enhle yokuhlunga izodala ukushintshashintsha okuzinzile phakathi kosuku nobusuku futhi inciphise izinkinga zokugxila noma ukushintsha kombala emini.
5. Ukuphathwa kwezindlu nokushisa
Ama-LED e-IR akhiqiza ukushisa. Ukwakheka komzimba wekhamera kunquma ukuthi lokhu kushisa kuhlakazeka kahle kangakanani. Ukushisa okweqile kunganciphisa isikhathi sokuphila kwe-LED futhi kwehlise ikhwalithi yesithombe.
Izinzuzo zokukhanya kwe-IR ku-CCTV
Ubuchwepheshe be-IR budumile ngoba bunikeza izinzuzo eziningi ezisebenzayo:
– Ukuqapha ebumnyameni obuphelele ngaphandle kokukhanya okwengeziwe.
– Akubonakali, kufanelekile ezindaweni zokuhlala ukuze kungaphazamisi.
– Ukusebenza kahle kwamandla, ngoba ama-LED e-IR ngokuvamile asebenza kahle kakhulu kunezibani ezimhlophe.
– Ukuqopha kuvumelana kakhulu ebusuku uma kuqhathaniswa nokuthembela ekushintsheni ukukhanya okuzungezile.
- Khulisa ukuphepha okuzungezile njengamagceke, amagalaji, amashede, kanye namaphasishi.
Ezimweni ezithile, i-IR iyisisombululo esilula kakhulu sokuthola izithombe zasebusuku ezingasetshenziswa njengobufakazi.
Imikhawulo nezinkinga ezivamile ze-IR CCTV
Nakuba kuwusizo, i-IR inemikhawulo okudingeka iqondwe ukuze kugwenywe ukulindela okungalungile:
1. Isithombe sivame ukuba mnyama nomhlophe
Ngenxa yokuthi imodi ye-IR ivame ukukhubaza ukukhiqizwa kombala, uma udinga umbala ebusuku, uzodinga obunye ubuchwepheshe (isb., "umbono wasebusuku ogcwele umbala" ngokukhanya okumhlophe noma inzwa ekhethekile).
2. Ukuzindla ngokweqile (ukuzindla kwe-IR)
Kumakhamera e-dome noma amakhamera afakwe eduze kwengilazi, i-IR ingabuyela emuva ilensini, idale isithombe esimhlophe/esinenkungu. Lokhu kuvame ukwenzeka uma uphawu lwerabha lungaqinile ngokwanele noma kunothuli esembozweni.
3. Ukuchayeka kakhulu ezintweni ezivaliwe
Uma into iseduze kakhulu nekhamera, ukubonakaliswa kwe-IR kungaba namandla kakhulu, okubangela ukuba imininingwane ilahleke (ukukhanya okumhlophe). Ukulungisa ubukhali be-IR noma isikhundla sekhamera kungasiza.
4. Ububanzi be-IR buvame ukuba “nombono ongcono”
Imininingwane yasefektri efana ne-“30 metres IR” ivame ukuba yizimo ezifanele. Ensimini, isimo sezulu (inkungu/imvula), umbala wento (ubumnyama bumunca i-IR), kanye ne-engeli yokuyifaka kunganciphisa ububanzi obusebenzayo.
5. Izinambuzane nothuli
I-IR idonsela izinambuzane. Izinambuzane ezindiza eduze kwelensi zizovela "njengezindilinga" ezinkulu futhi zingabangela ukutholwa kokunyakaza okungamanga.
Izinhlobo zekhamera ezine-IR: eyakhelwe ngaphakathi uma iqhathaniswa ne-IR yangaphandle
Kunezindlela ezimbili zokukhanyisa nge-IR:
– I-IR eyakhelwe ngaphakathi (ehlanganisiwe)
Kuvamile kumakhamera ezinhlamvu kanye ne-dome. Kulula, kubiza kancane, futhi kulula ukufaka. Kodwa-ke, ububanzi be-IR kanye nokusabalala kwayo kunqunyelwe usayizi wekhamera.
- Isibani se-IR sangaphandle
Kufakwa isibani se-IR esihlukile ngokwehlukile kwikhamera. Lokhu kuwusizo ezindaweni ezinkulu kakhulu noma uma ufuna ukubeka umthombo we-IR ukuze unciphise ukubonakaliswa. Lolu hlelo luguquguquka kakhudlwana, kodwa ludinga ukufakwa okucophelelayo nokubalwa kwama-engeli.
Ngezidingo zobungcweti ezifana namayadi amakhulu noma amaphethelo amade, izibani zangaphandle zivame ukunikeza imiphumela elinganayo.
Amathiphu okukhetha i-IR CCTV efanele
Ukuqinisekisa ukuthi utshalomali lwakho aluchithwa, cabanga ngamaphuzu alandelayo:
1. Qondanisa ububanzi be-IR nendawo
Kala ibanga lekhamera uze ufike endaweni ekude kakhulu ofuna ukuyibona. Khetha ikhamera enobubanzi obungokoqobo, bese ucabanga ngokungeza i-IR yangaphandle uma kudingeka.
2. Naka i-angle yelensi vs i-angle ye-IR
Amakhamera anamalensi ane-engeli ebanzi (isb., 2.8 mm) adinga ukusabalala kwe-IR ebanzi. Uma i-IR incane kakhulu, imiphetho yesithombe izoba mnyama.
3. Khetha i-850 nm noma i-940 nm njengoba kudingeka.
Ngokuqondene nemininingwane kanye nebanga, i-850 nm ivame ukuba ngcono. Ngokuqondene nokuqapha "okungabonakali", i-940 nm ifaneleka kakhulu.
4. Bheka isici sokusetha ukuqina kwe-IR.
Amakhamera avumela izilungiselelo zokukhanya ze-“Smart IR” noma ze-IR asiza ekunciphiseni ukuchayeka ngokweqile kwezinto eziseduze.
5. Naka ikhwalithi yesithombe ephansi yokukhanya.
I-IR akuyona yodwa into ebangela lokhu. Izici ze-sensor, i-ISP, kanye nokunciphisa umsindo (3D DNR) zithinta kakhulu imiphumela yokuqopha ebusuku.
Izindlela zokufaka ukuze uthole i-IR engcono kakhulu
Ukufakwa kahle kuvame ukunquma umphumela wokugcina:
– Gwema ukufaka ikhamera eduze kakhulu nezindonga noma ophahleni olungabonakalisa i-IR futhi ludale ama-flare.
– Ungadubuli ngengilazi ene-IR evuliwe. Uma kudingeka, cisha i-IR bese usebenzisa ukukhanya kwangaphandle.
– Hlanza isembozo selensi njalo ngoba uthuli nokungcola kwenza ukukhanya kwe-IR kube kubi kakhulu.
– Lungisa i-engeli yekhamera ukuze izindawo ezibalulekile (iminyango, amasango, iminyango yokungena) zibe sendaweni yokukhanya elinganayo.
– Cabanga ngokuphakama: okuphansi kakhulu kungonakala kalula, kanti ukuphakama kakhulu kungenza kube nzima ukubona imininingwane yobuso. Ngokuvamile, amamitha angu-2,5–3,5 avame ukukhethwa emakhaya, kodwa lungisa ngokufanele.
I-Penutup
Ubuchwepheshe bokukhanyisa i-IR kumakhamera e-CCTV buyisisekelo esibalulekile sokuqapha ebusuku. Ngokusebenzisa ama-LED e-infrared, izihlungi ezisikiwe nge-IR, kanye nezinzwa zekhamera ezizwelayo, i-CCTV ingaqopha umsebenzi ezimweni ezisukela ekukhanyeni okuphansi kuya ebumnyameni obuphelele. Kodwa-ke, i-IR iphinde iveze izinselele ezifana nokukhanya, ukuchayeka ngokweqile, kanye nobubanzi obusebenzayo obuncike endaweni ezungezile. Ngokuqonda umehluko phakathi kwe-850nm ne-940nm, ukukhetha ikhamera efanele, nokuyifaka kahle, ungafinyelela ukuqoshwa kwezithombe ebusuku okucacile, okuzinzile, nokuwusizo kakhulu ngezinjongo zokuphepha.
Uma ufisa, ngingaphinde ngilungise lesi sihloko sibe nenjongo ethile (isb., ibhulogi yesitolo se-CCTV, izinto zemfundo zesikole, noma isihloko sobuchwepheshe esijulile) bese ngengeza izinkomba zokucacisa kanye nezibonelo zokubala ububanzi be-IR.
