Yimiphi imisebenzi eyinhloko ekhamera ye-DSLR ethinta ukuchayeka okulungile kwesithombe?
Context:Ku-photography, i-exposure value (EV) yinombolo emele inhlanganisela yesivinini sokuvala sekhamera kanye nenombolo ye-f, ukuze zonke izinhlanganisela eziveza ukuchayeka okufanayo zibe ne-EV efanayo (kunoma yikuphi ukukhanya kwesigcawu esinqunyiwe). Inani lokuchayeka lisetshenziselwa futhi ukubonisa isikhathi esikalini sokuchayeka kwesithombe, umahluko we-1 EV uhambelana nesinyathelo sokuchayeka esijwayelekile samandla-ka-2, esivame ukubizwa ngokuthi ukumiswa.  Umqondo we-EV wasungulwa ngumenzi we-shutter waseJalimane uFriedrich Deckel ngawo-1950 (uGebele 1958; Ray 2000, 318). Inhloso yayo kwakuwukwenza kube lula ukukhetha phakathi kwezilungiselelo ezifanayo zokukhanyisa ikhamera ngokufaka inhlanganisela yesivinini se-shutter kanye nenombolo ye-f (isib., 1/125 s ku-f/16) ngenombolo eyodwa (isib., 15). Kwamanye ama-lens anamafasitela anezinhlamvu, le nqubo yaqhubeka yenziwa lula ngokuvumela izilawuli ze-shutter ne-aperture ukuba zixhunywe ngendlela yokuthi, lapho eyodwa ishintshiwe, enye yayilungiswa ngokuzenzakalelayo ukuze kugcinwe ukuchayeka okufanayo. Lokhu kwakuwusizo ikakhulukazi kwabaqalayo abanokuqonda okulinganiselwe ngemiphumela yesivinini se-shutter ne-aperture nobudlelwano phakathi kwabo. Kodwa yayisiza nabathwebuli bezithombe abanolwazi ababengase bakhethe isivinini se-shutter sokumisa ukunyakaza noma inombolo ye-f yokujula kwensimu, ngoba kwakwenza kube lula ukulungisa ngokushesha - ngaphandle kwesidingo sokubala ngekhanda - futhi kwanciphisa ithuba lokwenza iphutha lapho wenza ukulungiswa.
Uma ikhamera ye-DSLR ingasethwanga kwimodi ethi 'Automatic', kunemisebenzi emithathu eyinhloko okudingeka uyicabangele lapho unquma ngokukhanyisa okuyikho kwesithombe sakho. 1) I-Aperture - ukuthi i-aperture lens isethwe ibe nkulu kangakanani kunquma ukuthi kungakanani ukukhanya okungadlula ku-aperture. Isikhala esincane (isib. f/16) sivumela ukukhanya okuncane ukuba kufinyelele ku-sensor ngokungafani nesikhala esikhulu (isib. f/2.4). 2) I-Shutter Speed - isikhathi i-shutter evunyelwe ngaso ukuba ihlale ivulekile ngemva kokucindezela isivuli sekhamera. Isikhathi esifushane sokuchayeka (isb. 1/1000 sec) sizovumela ukukhanya okuncane ukuhlasela inzwa yekhamera ngenkathi ukuchayeka okude (isb. 1/4 sec) kuzovumela ukukhanya okuningi ukuhlasela inzwa 3) isilungiselelo se-ISO - lesi silungiselelo sisetshenziselwa ukulawula ukuthi inzwa izwa kanjani ekukhanyeni okuyihlaselayo. Ukusetha kwe-ISO ephansi (isib. i-ISO 200) kunomzwelo omncane kakhulu kunokusetha kwe-ISO ephezulu (isib. i-ISO 1600) okusho ukuthi ukukhanya okuncane kuyadingeka ukubamba isithombe ku-sensor. Yonke le misebenzi emithathu isebenza ngokubambisana ukuqinisekisa ukuthi inani elifanele lokuchayeka liyakhiwa ngokususelwa esithombeni nomphumela ozama ukuwakha.