Imbobo: Kuyini Emakhamera?

ngo kim Kubuyekezwe: June 28, 2022

Imbobo kubalulekile ikhamera isici esithinta inani lokukhanya elifinyelela inzwa yekhamera ekuchazweni okuthile. Imbobo ku-lens enquma ukuthi kungakanani ukukhanya okuvunyelwe ukudlula futhi kuzothinta ubukhali besithombe.

Imbobo iphinde ithinte ubukhulu bendawo okugxilwe kuyo. Kunoma yikuphi ukuchayeka okunikeziwe, imbobo encane izodala indawo enkulu lapho kugxilwe khona kuyilapho imbobo enkulu izodala indawo encane lapho kugxilwe khona.

Kulesi sihloko, sizoxoxa ngokuthi yini i-aperture nokuthi ingasetshenziswa kanjani ukuthola imiphumela engcono yezithombe:

Incazelo Yembobo

Imbobo isilungiselelo esikumakhamera ezithombe esilawula usayizi wokuvuleka kwelensi, noma iris. Inquma ukuthi kungakanani ukukhanya okuzodlula ukuze kufinyelele inzwa yesithombe. Usayizi wembobo uvamise ukuvezwa ngo f-izitobhi, futhi ingasukela kumanani aphansi (ukuvulwa okubanzi) kuya kumanani aphezulu (ukuvulwa okuncane kakhulu).

Ngokushintsha imbobo, awukwazi ukulawula kuphela ukuchayeka kwakho kodwa futhi neyakho ukujula kwensimu - kungakanani isithombe sakho esizogxila kukho. Inani lokuvula elikhudlwana lisho ukuthi isithombe sakho sizogxila kancane, sisenze sifiphale futhi sidale umphumela ofana nephupho. Ama-apertures amancane adala ukujula okuphezulu kwenkundla, okwenza konke kugxile - ilungele ukubukeka kwezwe kanye nezithombe zeqembu.

Indlela Isimbobo Esikuthinta Ngayo Ukuchayeka

Imbobo iyindawo elungisekayo engaphakathi kwelensi evumela ukukhanya ukuthi kudlule futhi kufinyelele inzwa yokuthwebula yekhamera. Ubukhulu balokhu kuvuleka bungashintshwa ukuze kulawulwe inani lokukhanya elingena kulensi. Lokhu kulawula kuvumela abathwebuli bezithombe ukuthi balungise ukuchayeka, noma ukukhanya, wezithombe zabo ezimeni ezihlukahlukene zokukhanyisa.

Uma ukukhanya kungena kulensi, kudlula endaweni eshintshwayo, ehlanganisa iringi enama-blade amaningi akha imbobo. Ama-blade angavuleka noma avale kuye ngokuthi kungakanani ukukhanya okudingekayo ukuze kuvezwe okulungile. Lokhu ngokuvamile kwaziwa ngokuthi usayizi wokuvula futhi kukalwa ngawo f-izitobhi – inani lenombolo ngokuvamile eliba phakathi f/1.4 kanye no-f/22 kwabaningi ama-lens. Imbobo enkudlwana isho ukuthi ukukhanya okwengeziwe kuzongena ekhamera, okuholela esifanekisweni esikhanya kakhudlwana; ngokuphambene, ngembobo encane, ukukhanya okuncane kuzongena kukhamera yakho okuholela esithombeni esimnyama.

Ukusetshenziswa kwama-f-stops ahlukene kuzophinde kuthinte ezinye izingxenye zokubukeka kwesithombe. Usayizi wokuvula omkhulu (ophansi f-stop) ingase idale ukujula kwenkundla okungashoni futhi ikhulise ukufiphala kwengemuva futhi ikhwalithi ye-bokeh; ngenkathi kusetshenziswa osayizi abancane bokuvula (i-f-stop ephezulu) kuzokhuphula ukujula kwenkundla ngenkathi kuncipha ukufiphala kwangemuva nezimfanelo ze-bokeh ezithombeni.

Izilungiselelo zokuvula ziyatholakala kumakhamera amaningi edijithali namuhla, amamodeli akhombayo nawokuthwebula kanye namakhamera e-DSLR athuthuke kakhulu anamalensi ashintshashintshayo. Ukwazi ukulungisa kahle ukulungiselelwa kuqinisekisa amazinga afanele wokuchayeka ezinhlobonhlobo zezithombe!

Ukuqonda Amanani Aperture

Imbobo yekhamera wukuvuleka kwelensi okuvumela ukukhanya kudlule futhi kufinyelele inzwa yesithombe. Imbobo ilinganiswa phakathi f-izinombolo, okuwumphumela wobude bokugxila kanye nosayizi wokuvuleka kwelensi.

Ukwazi ukulungisa inani lokuvula kuyisici esibalulekile ekuthwebuleni izithombe ezimangalisayo, ngakho-ke ake sibhekisise amanani okungena nokuthi zisebenza kanjani.

I-F-Stop kanye ne-T-Stop

Isikali esivamile sokulinganisa inani lokukhanya ilensi elivumela ukuthi lidlule saziwa ngokuthi f izitobhi or f-izinombolo. Izitobhi zika-F zisekelwe ku-a Isilinganiso, echaza ukuthi kungakanani ukukhanya okudluliselwa ilensi. Izimbobo ezinezinombolo zokuma eziphakeme zika-f zihambisana namalensi anamalensi amancane, avumela ukukhanya okuncane. Isibonelo, imbobo ye F / 2.8 singene ukukhanya okuphindwe kabili njengembobo ye F / 4.

Kusetshenziswa ifomula efanayo ukubala t-izitobhi, kodwa kunomehluko obalulekile phakathi kwawo nama-f-stops okufanele akhunjulwe lapho uthwebula ngamakhamera aqeqeshiwe. Nakuba amanani aveziwe angase afane (isb. F / 2 futhi T2), izitobhi zikala ukudluliswa kwangempela kuyilapho i-f-stop ikala ukukhanya ngokuqhathaniswa nosayizi wengane yokungena.

Ngamanye amazwi, zonke ezinye izinto ziyalingana, i-lens yamiswa f / 2 izovumela ukukhanya okuncane kunaku t/2 ngenxa yokulahlekelwa okuthile phakathi kwenzwa nalapho unquma khona inani lokuchayeka - ngokuvamile endaweni yokungena yamalensi akho. Ngaphezu kwalokho, uma ugxilisa ilensi eyodwa ku-infinity kuzo zombili izilungiselelo ze-t kanye ne-f-stop uzobona mayelana 1/3 EV umehluko (1 isitobhi) phakathi kwawo ngenxa yokulahlekelwa okudalwe ukuboniswa kwangaphakathi kuma-engeli amaningi wokusondeza lapho ume phansi ekuvulekeni kakhulu - ngakho akuwona wonke amalensi azoziphatha ngendlela efanayo nalapha!

Ububanzi Bokufaka

Imbobo isilungiselelo esilungisekayo kumakhamera edijithali alawula usayizi wokuvuleka kwe-diaphragm yelensi. Kuvame ukubizwa ngokuthi “f-stop” noma isilinganiso sokugxilile, futhi imelelwa uchungechunge lwezinombolo zika-f njenge f/2.8, f/5.6 njalo njalo. Lolu hlu, olwaziwa nangokuthi i- indawo yokuvula, ibhekisela ekuvulekeni kwamalensi amancane namakhulu kakhulu atholakala kukhamera ethile.

Ngokuvamile, indawo enenombolo ephansi izophumela ekuvulekeni okukhulu kwelensi, okuvumela ukukhanya okwengeziwe ukuthi kuthathwe inzwa nganoma yisiphi isikhathi. Lokhu kunemithelela emibili eyinhloko:

1. Izithombe ezikhanyayo ezinomsindo omncane
2. Ukujula komkhakha okusiza ukudonsela ukunaka esihlokweni esikhulu

Amanani asetshenziswa ngokuvamile aphansi afaka phakathi f/1.4 kanye no-f/2.8 amalensi agqamile adinga ukukhanya okuncane ukuze asebenze kahle. Amanani anezinombolo eziphakeme njenge f/11 noma f/16 ngokuvamile asetshenziswa ngamalensi ahamba kancane adinga ukukhanya okwengeziwe nganoma isiphi isikhathi ukuze kuthwebule izithombe ezihlanzekile ngaphandle komsindo omkhulu noma ikhwalithi yohlaza kuzilungiselelo eziphakeme ze-ISO.

Kafushane, ukuqonda Ububanzi Bokufaka kuhilela ukuqaphela ubudlelwano bayo phakathi kwezilungiselelo zokuzwela kwe-ISO kanye namazinga okukhanya - amanani aphansi okungena akhiqiza izithombe ezigqamile kuyilapho amanani okungena aphezulu angasiza ukugcina sonke isithombe sigxilile kuyilapho kufiphazwa imininingwane yangemuva lapho kudingeka izithombe ezijulile zenkundla.

Imbobo nokujula Kwensimu

Imbobo isilungiselelo kulensi yekhamera yakho esithinta ukuvezwa kwesithombe sakho. Futhi iyithuluzi elinamandla lokuthola isithombe esiqondile osifunayo. Ngokushintsha imbobo, ungakwazi ukulawula inani lokukhanya okungena kulens, kanye ukujula kwensimu.

Lesi sihloko sizohlola izinzuzo zokuvula futhi ukuthi kuthinta kanjani ukujula kwensimu.

Ukujula Kwenkambu Engajulile

Ukujula kwenkundla okungajulile kuwumphumela we-a indawo enkulu yokuvula. Ngokwandisa usayizi wembobo yakho (inombolo engu-f encane), kuzogxilwa kancane kwesithombe sakho, okuholela ekujuleni kwenkambu engajulile. Ukujula kwenkambu okungajulile kuwumphumela ofiselekayo wezithombe ezima ngobude, ukuthwebula izithombe ezinkulu kanye nesithombe sokwakheka kwezwe lapho ufuna ukuhlukanisa isihloko sakho nesizinda sazo noma ngaphambili. Yengeza idrama esithombeni futhi ingasetshenziswa ukudala izithombe ezinhle uma zisetshenziswe ngendlela efanele.

Ngokuvula indawo yakho yokungena (inombolo-f encane) nokusebenzisa i lens engile ebanzi ngebanga elifanele ukusuka esihlokweni, ungakwazi ukuthola imiphumela emihle ngempela ngezilungiselelo zokukhanya okuphansi njengokushona kwelanga noma endlini ngaphandle kokusebenzisa izilungiselelo eziphakeme ze-ISO. Kufanele futhi usebenzise ukukhanya kwangaphandle okukodwa noma okubili noma ithuluzi lokukhanyisa ukuze uphelelise ukucaca nokuthola lokho kubukeka kwekhwalithi yobungcweti kwezithombe zakho. Inhlanganisela ye izimbobo ezinkulu (f/2.8 – f/4) ezinobude bokugxila obufushane (14mm – 50mm) lapho uthatha izithombe ngokukhanya okuphansi ngokuvamile kusebenza kahle!

Ukujula Kwenkambu

Ukujula kwenkambu kwenzeka lapho uhla olukhulu lwezinto lugxilile phakathi kwesithombe. Uma uthwebula ngokujula kwenkambu, kubalulekile ukusebenzisa indawo enkulu yokuvula futhi unciphise ukugxila kwakho kungemuva nangaphambili kwesithombe. Ukuze ufinyelele lokhu, uzodinga ukusetha indawo yokuvula ikhamera yakho ibe isilungiselelo sayo esincane kakhulu. Ngokwenza lokhu, ukukhanya okungena kwilensi kungavinjelwa nakakhulu, kwandise ukujula okuphelele kwenkambu.

Ukujula kwenkundla kunqunywa inhlanganisela yezinto ezifana nalezi i-shutter isivinini kanye nobude bokugxila kwelensi - kokubili kuxhumene. Uma udubula ngelensi ene-engeli ebanzi (lapho ukukhanya kungena ngokukhululeka futhi kukhiqiza ukujula okungashoni), ukusebenzisa isivinini sokuvala esihamba kancane ngenkathi uhlehlisa futhi ugxile ezintweni ezikude kuzoholela ekujuleni okujulile kwenkambu ebanjiwe. Ngokufanayo, lapho udubula nge-telephoto lens (lapho kungena ukukhanya okuncane kuphela) ngesivinini se-shutter esheshayo izokwandisa ukugxila ezintweni eziseduze okuholela ekujuleni okujulile futhi.

Imbobo nokufiphalisa ukunyakaza

Imbobo ingenye yezingxenye ezibaluleke kakhulu zekhamera. Kuyimbobo kulensi elawula inani lokukhanya ilensi elingenisayo. Imbobo iphinde ibe nomthelela oqondile ukujula kwensimu, okuyindawo yesithombe okugxilwe kuyo. Ngaphezu kwalokho, indawo yokuvula nayo idlala indima enanini le ukufiphala kokunyakaza ekhona esithombeni.

Kulesi sihloko, sizobheka eduze ubuhlobo phakathi indawo yokungena nokufiphala kokunyakaza.

Imbobo esheshayo

A ukuvuleka okusheshayo iyilensi enendawo ebanzi evumela ukukhanya okwengeziwe ukuthi kungene inzwa yekhamera lapho ithwebula izithombe noma ividiyo. Uma indawo evulekayo iba banzi, kungasetshenziswa isivinini esisheshayo se-shutter, okuyinzuzo ekuthwebuleni izinto ezihambayo. Kuphinde kunciphise isidingo sokukhanyisa okwenziwa ezimweni ezithile. Ngamanye amazwi, ilensi yokuvula esheshayo izokuvumela ukuthi uthathe izithombe ekukhanyeni okuphansi ngaphandle kokufiphala noma umsindo ngenxa yesivinini esinesivinini sokuvala noma izilungiselelo eziphezulu ze-ISO.

Izimbobo ezisheshayo zivame ukubizwa ngokuthi izimbobo ezinkulu or izinombolo eziphansi ze-f (ngokuvamile f/2.8 noma ngaphansi). Imbobo enkulu ihlinzeka ngokujula kwenkambu, okukuvumela ukuthi ufiphaze ingemuva futhi udale izithombe ezikhangayo zesithombe. Lapho uthwebula indawo nezakhiwo, ukuba nelensi ye-engeli ebanzi enezinombolo zika-f ezincane kubaluleka kakhulu njengoba ingavumela ukukhanya okwengeziwe kuyilapho igcina indawo elungile yokuqamba kwakho ibukhali.

Uma isimbobo siba sikhulu, izikhathi zakho zokuchayeka zingaba zifishane lapho uthwebula izinto ezihambayo (isb, izimoto) noma ugwema ukunyakaziswa kwekhamera (isb., izithombe zasebusuku eziphathwa ngesandla). Ngelensi eshesha kakhulu njenge- f/1.4 okuyinhloko, abathwebuli bezithombe bangathembela ekujuleni okubanzi kokulawulwa kwenkundla kanye nokukhanya kwemvelo ukuze bathole amashothi okudala ngaphandle kokufiphala kokunyakaza konakalise ukuqanjwa kwabo—ilungele izithombe zasebusuku nezigcawu zasemadolobheni!

Imbobo Enensayo

Omunye wemisebenzi eyinhloko yokuvula kancane ukufiphala kokunyakaza. Ngokunciphisa usayizi wokuvula, kunikezwa isikhathi esengeziwe sokuba ukukhanya kudlule ilensi, ngokwenza kube lula ukuthwebula ukunyakaza futhi kubukeke njengokufiphala kobuciko. Uma udubula isihloko esihamba ngokushesha, ukusetha indawo yokuvula izitobhi ezimbalwa kancane kuzothwebula ukunyakaza kwayo ezithombeni ezimbalwa ngokuhamba kwesikhathi futhi kuholele ekutheni ukufiphala kokunyakaza.

Nakuba isivinini se-shutter esinensa kancane singaphinda simise ukunyakaza, ukusebenzisa indawo engena kancane kusiza ukudala isikhathi eside sokuchayeka ngaphandle kokwenyusa i-ISO noma ukwehlisa isivinini sokuvala. Kanjalo, ungakwazi ukusebenza kalula eduze kwanoma yiziphi izimo zokukhanya okuphansi ezingase zidinge okukodwa noma kokubili kwalokho kulungiswa.

Ngaphezu kwalokho, ukunciphisa usayizi wokuvula kunikeza okukhulu ukujula kwenkambu (ebuye ibizwe ngokuthi isizinda), okukuvumela ukuthi uhlukanise isihloko sakho endaweni esizungezile futhi ugxile kulokho ofuna ukukubonisa esithombeni sakho. Lo mphumela usetshenziswe iminyaka eyishumi emva kweshumi leminyaka ekuthwebuleni izithombe; isibonelo, ukufiphalisa eminye imininingwane noma abantu okungenzeka bayaphazamisa embonweni wakho wasekuqaleni ngokubabeka ngokungacacile ngaphakathi kokubhaliwe kuzosiza ukugxilisa ukunaka kabusha esicini sakho esiyinhloko futhi kuthuthukise ukubaluleka kwaso ezibukelini.

Imbobo kanye Nokukhanya Okuphansi

Imbobo inomthelela oqondile ezithombeni zakho ezithathwe ezindaweni ezinokukhanya okuphansi. Ezithombeni, lokhu kubhekisela kusayizi wembobo yelensi elawula inani lokukhanya elingena kunzwa yekhamera. A indawo enkulu yokuvula ivumela ukukhanya okwengeziwe, okuholela esithombeni esigqamile. A ukuthambisa okuncane ivumela ukukhanya okuncane, futhi idinga isikhathi esengeziwe ukuze ikhiqize isithombe esigqamile. Lokhu kungaba usizo ikakhulukazi ku izimo zokukhanya okuphansi.

Izithombe Eziphansi Zokukhanya

Lapho uthwebula izithombe ezimweni eziphansi zokukhanya, ukuqonda ukuma kwe-cone kanye izilungiselelo zokuvula kubalulekile. Imbobo ingusayizi wesikhala esingaphakathi kwediaphragm yelensi yekhamera kanjalo nenani lokukhanya elithwetshuliwe. Izimbobo zisukela F2 kuya kuF16 kanye nanoma yikuphi ukulungiswa okuyingxenye phakathi, kuye ngemodeli yekhamera.

Uma isimo sokuthatha izithombe sidinga imininingwane eyengeziwe noma ukuqhathanisa, bese ukhetha indawo encane yokungena -- ukuvala noma ukunciphisa ukuvuleka kwelensi -- kuyadingeka. Osayizi bokuvuleka abancane balawula amanani okukhanya anembe kakhudlwana afinyelela inzwa yekhamera okuholela ezithombeni ezicijile ezindaweni zokukhanya okuphansi.

Abathwebuli bezithombe abaningi abanolwazi bayakulangazelela ukukhumbula izilungiselelo ezinkulu zokuvula, njenge F2, vumela ukukhanya okwengeziwe kuyilapho osayizi bembobo abancane njenge F4 izonciphisa ukukhanya okungenayo, ikwenze kube nzima nakakhulu uma uthwebula ezindaweni ezinokukhanya okuphansi. Uma ubhekene nobumnyama noma izimo zokukhanya ezingavamile njalo kwandisa isivinini sakho sokuvala kanye ne-ISO esikhundleni sokushintsha izilungiselelo zokuchayeka ezakhelwe ngaphakathi zekhamera yakho; lokhu kugcina i-pixilation engaguquki ezithombeni kuyilapho kunikeza imininingwane ebabazekayo uma iphrintiwe ngosayizi ogcwele -- ifaneleka kangcono omagazini abacwebezelayo namaphosta!

Izilungiselelo Zembobo Ebanzi

Ukuze izithombe ezikhanyayo eziphansi, izilungiselelo zokuvula okubanzi (iphansi f/inombolo) kungaba yinzuzo ngokuvumela ukukhanya okwengeziwe kudlule kulensi kungene kuyinzwa yekhamera. Indawo ebanzi iphinde isize ukunciphisa ukuzamazama kwekhamera ngenxa yezikhathi zokuchayeka ezinde ezidingekayo ezimeni eziphansi zokukhanya. Ukuze kuzuzwe ukujula okungajulile kwemiphumela yenkambu noma ukugxila okukhethiwe, izimbobo ezibanzi noma izilungiselelo eziphansi ze-f/inombolo ziyanconywa.

Uma ukhuphula usayizi wokuvula kwakho, usayizi "wesitobhi" ngasinye esikalini uyashwabana futhi ngaleyo ndlela inani lokukhanya elingene likhuphuke ngamandla. Lokhu kusho ukuthi uma uphinda kabili usayizi wakho wokuvula usuka ku-f-stop uye kwenye, uyavumela ukukhanya okuphindwe kabili phakathi ngesinyathelo ngasinye uye phezulu futhi lapho usuka kokukodwa uye phansi uyasihlehlisa ngohhafu.

Uma uthwebula ezimweni zokukhanya okuphansi, kubalulekile ukwazi ukuthi isitobhi ngasinye sikuthinta kangakanani ukuchayeka nokuthi ungakanani umsindo odalwa ngokushintsha kokuma ngakunye. Ngokuvamile, isitophu ngasinye osinyusayo sicishe sibe Umsindo ophindwe kabili ehlotshaniswa nayo ngenxa yokuba nama-photon amaningi ashaya inzwa nganoma isiphi isikhathi futhi ngaleyo ndlela yethula umehluko omkhulu phakathi kwawo.

Sawubona, nginguKim, umama kanye nomshisekeli we-stop-motion onesizinda ekudalweni kwemidiya nokuthuthukiswa kwewebhu. Nginothando olukhulu lokudweba nokugqwayiza, futhi manje sengingena ngekhanda emhlabeni onyakazayo. Ngebhulogi yami, ngabelana ngezifundo zami nani bafana.