I-F-Stop Noma I-Focal Ratio: Iyini Futhi Kungani Ibalulekile

ngo kim Kubuyekezwe: June 28, 2022

F-yeka or isilinganiso sokugxila (ngezinye izikhathi kuthiwa yi-f-ratio noma isihlobo ukuthambisa) igama elisetshenziswa ekuthwebuleni izithombe futhi libhekisela kusilinganiso phakathi kobude obugxilile belensi kanye nobubanzi bomfundi wokungena.

Le parameter ibalulekile ukuthi uyiqaphele uma udubula nge- ikhamera, njengoba kuthinta inani lokukhanya elidlula ilensi. Uma inombolo ye-F-Stop inkulu, imbobo incane, futhi ngaleyo ndlela ukukhanya okuncane okuvunyelwe ukungena.

Lesi sihloko sizohlola umqondo we-F-Stop ngokuningiliziwe futhi sichaze kungani kubalulekile ukuqonda lapho ukudubula.

Yini i-F-Stop?

F-Misa (obeye aziwe njengo isilinganiso sokugxila) isici sokuthatha izithombe esihlobene nenani lokukhanya okungaqoqwa ilensi, noma ikhono layo lokunciphisa usayizi wembobo. Ikalwa njengesilinganiso phakathi kosayizi womfundi wokungena ilensi kanye nobude bokugxila, futhi ichazwa inombolo elandelwa f, njenge f / 2.8. Uma le nombolo iba ncane, iba nkulu umfundi wokungena, okuholela ekukhanyeni okwengeziwe okukwazi ukungena. Ngokuphambene, ukuba nenombolo enkulu ye-f-stop kungasho ukuthi ukukhanya okuncane kukwazi ukungena ngelensi yakho kanye nendawo yokuvula.

I-F-Stop iphinde isebenze ngokubambisana i-shutter isivinini; uma wazi isici esisodwa ungakwazi kalula ukubala esinye. Kuwusizo futhi ekugxileni entweni esondelene njengezithombe ngokwandisa inombolo yakho ye-f-stop kanye nokuvumela ukulawula okungcono kokugxila phezu kwamashothi akho; lokhu kuhlanganisa zonke izinhlobo zokuthatha izithombe kusukela ezilwaneni zasendle kuye ekuthwebuleni izithombe zemvelo, kodwa kuya ngokuya kubaluleke kakhulu ekuthwebuleni izithombe lapho ingemuva lidinga ukufiphazwa ukuze ugxile esihlokweni sakho kuphela. Inombolo enkulu ye-f-stop ivumela ukufiphala okwengeziwe kwengemuva kanye nokulawula okugxilile okungcono kumabanga aseduze noma ukujula okungajulile kwamashothi enkambu.

Zonke ama-lens babe nezici ezihlukene ezithinta amandla wabo we-f/number; ngenxa yalokhu ungase ufune amalensi amaningi atholakalayo ukuze ahlangabezane nezidingo zakho ezithile lapho uthwebula izithombe noma amavidiyo. I-focal ratio nayo isebenza ngendlela ehlukile kuye ngosayizi wenzwa; amakhamera ozimele ogcwele ngokuvamile anokujula kwenkambu okungashoni kakhulu kunamakhamera asikiwe ngenxa yosayizi wawo omkhulu wezinzwa—okusho ibanga elide phakathi kwezinto ukuze lezi zinto zihlale zigxilile ngesikhathi esisodwa ngaphakathi kohlaka lwakho. Ukuqonda ukuthi kanjani Izilinganiso zokugxila ingaba nomthelela kumakhono ekhamera yakho ingakusiza wenze izinqumo mayelana nokuthi imaphi amalensi afaneleka kangcono imisebenzi ehlukahlukene kanye nokuthi angathinta kanjani ikhwalithi iyonke lapho usebenza namaphrojekthi ahlukene noma izimo zokudubula.

Iyini i-Focal Ratio?

Isilinganiso sokugxila, okuvame ukubizwa ngokuthi f-stop, isilungiselelo sesivinini se-shutter esivezwa ngokwenani lezitobhi noma usayizi wokuvuleka kwelensi okudalwe ilensi. Uma inombolo iyinkulu, kuncane ukuvuleka kwelensi nokukhanya okuncane okufinyelela inzwa yekhamera yakho. Ngokuvamile isukela f / 1.4 kuye ku-f / 32 kumalensi amaningi kodwa angaya phezulu kakhulu uma udinga ukuthwebula ukukhanya ukude.

Isilinganiso sokugxila ibalulekile ngoba ilawula ukuthi kungakanani ukukhanya okufinyelela inzwa yekhamera yakho, okukuvumela ukuthi uthwebule isithombe esivezwe kahle ngaphandle kokusidalula ngokweqile noma ukusiveza kancane. Inombolo ephansi ikunikeza ukujula kwenkambu okungajulile kuyilapho ephakeme izokunikeza ukujula okukhulu nokugxila okucijile ezintweni ezikude. Isivinini se-shutter esinensayo sidinga i-f-stop eyengeziwe kuyilapho isivinini sokuvala esisheshayo sidinga i-f-stop encane; ngakho ukudubula ngenani elikhulu lokukhanya kudinga i-f-stop encane kuyilapho ukudubula ekukhanyeni okuphansi kudinga okufana ne- F8 noma ngaphansi ngezilungiselelo ezifanele ze-ISO. Ukukhula okubukhali lapho uyeka phansi (wehlisa i-F-Stop yakho) nakho kwengeza ekubukhalini kwesithombe kukonke.

Uma ushintsha i-F-Stop yakho, khumbula ukuthi ukwenyuka ngakunye phezulu noma phansi kuhambisana noshintsho ekuchazweni ngokuma okukodwa (okulingana nokuphinda kabili noma ukunciphisa inani lokukhanya ngohhafu). Ngalokhu kuqonda, umuntu angalungisa isilinganiso sazo sokugxila ngokusekelwe emazingeni okuchayeka afiselekayo kanye nokujula okufiselekayo komphumela wenkambu wamaphrojekthi abo wokuthatha izithombe.

Ukuqonda i-F-Stop

F-yeka, obeye aziwe njengo isilinganiso sokugxila, kuwumqondo obalulekile ezithombeni nakuvidiyo, odlala indima enkulu endleleni izithombe zakho eziphuma ngayo. I-F-stop isilinganiso phakathi kwamalensi ubude bokugxila kanye nobubanzi bomfundi wokungena. Ivezwa njengenombolo, futhi ingasukela kokuphansi kwe f/1.4 yonke indlela kuze kufike ku-f/32 noma ngaphezulu. Ukuqonda i-F-stop kubalulekile kunoma ubani ofuna ukuthola izithombe ezingcono.

I-F-Stop ikuthinta kanjani ukuchayeka?

Lapho umthwebuli wezithombe elungisa imbobo (F-Misa) yelensi, ithinta ngokuqondile ukuthi kungakanani ukukhanya okungena kulensi nenzwa. I-F-Stop ephansi ivumela ukukhanya okwengeziwe kuyilapho inombolo engu-F ephezulu ikukhawulela. Ngokuvula imbobo nge-F-Stop ephansi, udala indawo yokugxila ebanzi evumela ukukhanya okwengeziwe ukuthi kungene futhi kusize ekudaleni ukujula kwenkambu engashoni eziboleka kahle ku-portraiture nanoma yisiphi isithombe esidinga izendlalelo ezingajulile nokuhlukaniswa. Ukwengeza, lokhu kungaba yinzuzo ezimweni zokukhanya okuphansi lapho kungekho khona ukukhanya okwanele ukuze kuvezwe kahle uhlaka.

Ukudayela i-F-Stop efanelekile yesigcawu nakho kuthinta ngokuqondile isikhathi sokuchayeka, esingalungiswa ngesivinini sokushutha kumakhamera amaningi uma esethelwe kumodi yokwenziwa ngesandla. Ukuze ugcine ingemuva osihlosile noma isihloko sigxile kakhulu, yehlisa isivinini sokuvala bese ulungisa indawo ovula kuyo ukuze isithombe sakho sivezwe kahle ngesikhathi esifanele - futhi ungakhohlwa mayelana Ukulungiswa kwe-ISO kanjalo!

Umqondo obanzi ngemuva kwe-f/stop yilokho imbobo yokulinganisa kanye nesivinini se-shutter yizici ezibalulekile zokuthatha izithombe ngempumelelo; kokubili kuthinta ukuthi inzwa yekhamera ibonakala isikhathi esingakanani ekukhanyeni okungenayo. Uma uthwebula Ngemanuwali, kufanele ucabangele zontathu izici lapho uzama ukuthola izithombe ezivezwe kahle:

• Izilungiselelo ze-ISO (noma ukuzwela kwefilimu)
• isivinini se-shutter
• f/stop/aperture ngokufaka uzimele okuhlukile njengokujula kokulawula kwenkambu noma isithombe sesibaluli esifiphalisa ukunyakaza.

Buyini ubudlelwano phakathi kwe-F-Stop ne-Focal Ratio?

F-Misa isilinganiso sobude obugxile kulensi nobubanzi bayo. Lapho i-F-Stop iphakama, imbobo iba yincane futhi iba nkulu ukujula kwenkambu esithombeni esinikeziwe. I-F-Stop isetshenziselwa ukunquma ukuthi kungakanani ukukhanya okufinyelela inzwa yekhamera kanye nokuthi imbobo ibanzi noma incane kangakanani kulensi ethile.

I-Focal Ratio, noma f / yima ngamafuphi, kungacatshangwa njengengxenye eyodwa yohlu ekutshela ngenhlanganisela yekhamera yakho nelensi. Uma ubhekisela ku-f-stop ezithombeni, iphathelene kakhulu nezilungiselelo zokuvula indawo. Njengesivinini se-shutter, izilungiselelo zokuvula ziyakwazi ukulungisa inani lokukhanya elidlula kumalensi akho futhi lingene kunzwa yesithombe sakho (noma ifilimu). Izitobhi zika-f ezinezinombolo eziphansi zizodala ukukhanya okwengeziwe kuyilapho izitobhi ezinezinombolo eziphakeme zinciphisa ukukhanya okudlulayo. Ngakho-ke, izitobhi ezinezinombolo eziphansi zizodala izithombe ezigqamile ezinobubanzi obungashoni benkambu kuyilapho izitobhi ezinezinombolo eziphakeme ziholela ezithombeni ezimnyama ezinobubanzi obugxilwe obunyukile noma ukujula kwenkambu (okuhlobene: Kuyini Ukujula Kwenkundla?).

Enye ingxenye kulolu hlu ibizwa ngokuthi “ubude obugxile” okusho ukuthi “ibanga.” Lokhu kunquma ukuthi ungagxila kangakanani noma ukude kangakanani kunoma yisiphi isihloko - njengalawa masayizi amalensi ekhamera achazwe kulesi sihloko (okuhlobene: Ukuqonda Amasayizi Amalensi Ekhamera). Amalensi amaningi kulezi zinsuku amalensi okusondeza okusho ukuthi anobude bokugxila obulungisekayo ukuze usondele noma uqhelelene nesihloko sakho ngaphandle kokuthi uzinyakazise ngokwakho.

Ngakho-ke kwenzekani ngempela uma ulungisa eyakho F-yeka? Njengoba kushiwo ngenhla ihlobene nokuthi kungakanani ukukhanya okudlula ilensi yakho ngakho-ke uma uyilungisa lokho okwenzayo ukwenza ukulungisa phakathi kokuchayeka okuphezulu kanye nokujula okuncane kwenkambu etholakalayo ekudubuleni okuthile. Ngezinombolo eziphansi ezivumela ukukhanya okwengeziwe ukuze uthole amashothi agqamile kodwa afiphele kanye nezinombolo eziphakeme ezinikeza okumnyama kodwa okucijile. Kungakho ukudlala ngezilungiselelo ezinjalo ezithombeni kungaba nomthelela omkhulu emazingeni okuchayeka kanye nebanga lokugxila ngaphakathi kwanoma yikuphi ukwakheka - yingakho ukwazi nge-F-Stop kanye nezilinganiso zokugxila kufanele kucatshangelwe njalo ngaphambi kokuthwebula isithombe!

Ukuqonda I-Focal Ratio

F-Misa, eyaziwa ngokuthi yi isilinganiso sokugxila, kuwumqondo obalulekile ezithombeni obhekisela kusayizi wembobo kwilensi yekhamera. Iyingxenye evame ukubhalwa njengenombolo, njenge f/2.8 noma f/5.6.

Ukuqonda umqondo we F-Misa kubalulekile kubathwebuli bezithombe ngoba kubasiza ukwazi ukuthi kungakanani ukukhanya abakudingayo ukuze baveze obala isithombe ngendlela efanele. Ngaphezu kwalokho, kuthinta futhi ukujula kwensimu, okuyibanga lesithombe esigxilile. Ake sijule kancane futhi sifunde kabanzi mayelana F-Misa kanye nokubaluleka kwayo.

Buyini ubudlelwano phakathi kwe-Focal Ratio kanye nenkundla yokubuka?

Lapho uthwebula isithombe, i- isilinganiso sokugxila - evame ukubizwa ngokuthi i- f-stop – kungenye yezinto ezibaluleke kakhulu okufanele zicatshangelwe. Isetshenziselwa ukulawula usayizi wesithombe inkambu yokubuka, noma singakanani isigcawu ongasithwebula esithombeni. Inombolo ephezulu ye-f-stop izoveza isithombe esibanzi, kuyilapho inombolo ephansi izokhiqiza isithombe ngaso ukujula okulinganiselwe kwenkambu.

I-focal ratio nayo ithinta i- ukujula kwensimu esithombeni noma kuvidiyo yakho uma isetshenziswa namalensi ahlukene. Lapho idubula endaweni ebanzi (i-f-stop ephansi), ikhiqiza ukujula kwensimu encane kakhulu. Ngokuphambene, ukusebenzisa ama-f-stops kuzodala ukujula okwengeziwe kodwa kungabangela ukufiphala okuthile ngemuva nezindawo ezingaphambili ngenxa yokuphazamiseka okwengeziwe okwenzeka ezingxenyeni ezincane zozimele wakho.

Ubudlelwano phakathi kwe-focal ratio nenkundla yokubuka bucacile; ukuthi ama-f-stops aphezulu adala izithombe ezincane futhi ngokuphambene nalokho. Lokhu kusho ukuthi lapho uthwebula indawo noma ezinye izigcawu ezinkulu ezinezihloko ezikude, uzodinga ilensi ebanzi kakhulu (ene-f-stop ephansi ngokufanelekile) noma ungasebenzisa amalensi amaningi ngezilinganiso ezihlukile zokugxila ukuze uthole inhlanganisela efanele yokuthwebula. zonke izici zesihloko sakho.

Ingabe i-Focal Ratio ikuthinta kanjani ukujula kwenkambu?

Isilinganiso sokugxila (owaziwa nangokuthi f-stop) ingenye yezici ezibalulekile ezithombeni, ngokuvamile zichazwa ngo-'f/' ngaphambi kwenombolo. Ikakhulukazi, isilinganiso sokugxila esihlobene ne ukujula kwenkambu kanye nemiphumela yokuchayeka okungaba nomthelela emiphumeleni yezithombe zakho.

Ukujula kwenkambu kubhekise ekutheni singakanani isigcawu esibonakala sigxile kukho. A ukujula kwensimu okungashoni ingenye lapho ingxenye yesigcawu ivela khona lapho kugxilwe khona ngenkathi a ukujula okubanzi kwenkundla yileyo lapho yonke into ibonakala ibukhali. I isilinganiso sokugxila sidlala indima ebalulekile ekunqumeni inani lokujula elifakwe esithombeni.

Isilinganiso esikhulu sokugxila (isibonelo, f / 11) ivumela a ukujula okubanzi kwenkundla lokho kuhlanganisa kokubili izakhi eziseduze nezikude kanye nakho konke okunye phakathi kwazo. Lolu hlobo lwesilungiselelo lungase lusebenze kahle kakhulu kukwakheka kwezwe noma izithombe zangaphandle ezidinga ukufaka kokubili izici ezingaphambili nengemuva ezinobukhali obukhudlwana nokucaca okukhulu. Ngalesi sizathu, abathwebuli bezithombe abaningi abangochwepheshe bavame ukukhetha ama-f-stops amakhulu amashothi angaphandle.

Nokho, lapho ukudubula izifundo eduze - ezifana i-portrait photography noma i-macro photography - kungase kufiseleke ukusebenzisa izilinganiso zokugxila ezincane (njengokuthi f/1.4). Lezi zilungiselelo ziyakuvumela amasimu ukujula angajulile okusiza ukuhlukanisa isihloko kusizinda saso, ukudala umphumela omangalisayo futhi ocacile ngamaphuzu ahlukanisiwe kahle ekugxilweni phakathi kwendawo ezungezile efiphele.

Isiphetho

F-yeka or isilinganiso sokugxila kuwumqondo obalulekile ukuze abathwebuli bezithombe bawuqonde. Kuyasiza ukuchaza ububanzi bamanani wokuvula, kanye ukujula kwensimu. Ukuqonda lo mqondo kusiza ekuqondeni indlela yokusebenzisa amalensi ahlukene namakhamera ukuze uthole imiphumela oyifunayo. Ngaphezu kwalokho, kuyasiza futhi ekuqinisekiseni ukuthi uthola isithombe osifunayo ngokulawula inani lokukhanya okungena kukhamera.

Ukuphetha, kubalulekile ukuthi abathwebuli bezithombe baqonde umqondo we f-stop or isilinganiso sokugxila ukuqinisekisa ukuthi izithombe zabo zibukeka ziphelele.

Kungani i-F-Stop ne-Focal Ratio ibalulekile kubathwebuli bezithombe?

Kwabathwebuli bezithombe, i f-stop futhi isilinganiso sokugxila yizici ezibalulekile zokuqonda ukuchayeka, ukucija kwelensi kanye ne-bokeh. I isilinganiso sokugxila ibhekisela kusayizi wokuvuleka kwelensi, noma indawo, okusiza ukunquma ukuthi kungakanani ukukhanya okuvunyelwe ngelensi ukuze kufinyelele inzwa yekhamera. Lapho umthwebuli wezithombe eshintsha usayizi wembobo ngokusebenzisa okuhlukile f-izitobhi, izothinta izithombe zabo eziwumphumela ukujula kwensimu.

Okukhudlwana inombolo ye-f-stop izodala indawo encane eholela ekujuleni okukhulu kwenkambu ngokugxila okwengeziwe - lokhu kungaba isilungiselelo esihle kakhulu izithombe ze-landscape ngakho uthola konke kugxile. Inombolo encane izokunikeza indawo enkulu yokuvula nokushona okungashoni kwenkundla okwenza isihloko sakho sigqame kakhulu - lokhu kungaba ngcono kakhulu izithombe zesithombe lapho ufuna ukufiphalisa kuzo zombili izinhlangothi zesihloko sakho sokuma ngobude.

Ngaphezu kokusiza ukulawula ukuchayeka, I-F-stop ne-Focal Ratio futhi ibe nomthelela ekubukhalini lapho usebenzisa amalensi anokulungiswa okulinganiselwe; usebenzisa imbobo encane (izinombolo eziphezulu ze-f-stop) kungasiza ekunciphiseni ukuthamba okuthile ngenxa ye-diffraction kanye ne-vignetting. Ngokuqonda lezi zindinganiso ezimbili, umthwebuli wezithombe angakwazi kahle lungisa izilungiselelo zekhamera yabo ngokwemibandela yokudubula ukuze khulisa ikhwalithi yesithombe, setha izithombe ezivezwe ngokunembile ezimeni zokukhanya ezinzima futhi uzuze imiphumela yobuciko oyifunayo ngokulawula ukujula kwenkundla ngenkathi usebenza ngama-primes noma ama-zoom anokulungiswa okulinganiselwe.

Ukhetha kanjani i-F-Stop ne-Focal Ratio efanele yesithombe sakho?

Ukukhetha i-F-Stop ne-Focal Ratio efanele ngoba ukuthatha kwakho izithombe kuyisilinganiso esibalulekile somphumela oyimpumelelo. Imithelela yalawa ma-lens ezithombeni zakho izonqunywa amapharamitha owasethela wona lapho ukhetha isivinini se-shutter ne-aperature oyifunayo.

Okokuqala, kufanele uhlole oyifunayo ukujula kwensimu uhlela ukufeza esithombeni sakho. Uma kufunwa ukujula kwenkambu engajulile, khona-ke ama-F-Stop amancane afana nalokhu f/2 noma f/2.8 kufanele yamukelwe. Ngakolunye uhlangothi, uma kuyinto efiselekayo ukubamba izibalo eziningi ngokucacile okulinganayo bese kuba nezinombolo eziphezulu ze-F-Stop ezisukela ku- f / 5 kuye ku-f / 22 kufanele isetshenziswe esikhundleni.

Kuyaphawuleka ukuthi njengoba amalensi asheshayo ejwayele ukubiza imali eningi kunamalensi ahamba kancane, umuntu kufanele anake kakhulu ibhajethi yawo lapho ekhetha isivinini sokuvala isivalo esikhulu futhi ngokuphambene aphinde aqaphele ukuthi kungakanani ukukhanya adinga ukuthwebula lapho ehlola indawo yawo yokuvula. izilungiselelo. Kungaba ukuhlakanipha futhi ukubhekisela kumamanuwali abasebenzisi noma okokufundisa okuku-inthanethi okuchaza ukuthi yiluphi uhlobo lwamalensi nokulungiselelwa okufaneleka kangcono kusimo ngasinye ukuze ukwazi ukukwazi ngempela la mapharamitha ngokuhamba kwesikhathi. Ekugcineni, ayikho impendulo eqondile futhi ukuqonda okuncamelayo komuntu siqu ngokusebenzisa ukuhlola kuzosiza ubuciko bokuthola izithombe ezisezingeni eliphezulu ngokuhamba kwesikhathi!

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.