Kuningi kunenzwa yesithombe kunezinombolo zamaphikseli.
Inzwa yesithombe ku-camcorder (noma ikhamera yedijithali) yilokho okubeka "idijithali" ibe ikhamera yedijithali. Ngokumane nje, inzwa yesithombe iguqula ukukhanya okuthunjiwe yilensi yakho yekhamera bese uyibuyisela isignali yedijithali. Lokho ukukhanya okugcizelelwe kukhishwa bese kugcinwa kwimemori yakho ye-camcorder njengefayili yevidiyo yedijithali ongayibuka kamuva kukhompyutha yakho noma ku-TV. Eceleni kwe-lens ngokwayo, inzwa yesithombe yinto ebalulekile eqinisekisa ividiyo yekhwalithi.
Kunezinhlobo ezimbili eziyinhloko zamenenja yesithombe se- camcorder : i- CCD (ukushaja idivayisi ehlanganisiwe) ne- CMOS (complementary metal oxide semiconductor). Zombili izinhlobo zobuchwepheshe bezinzwa zesithombe ziqukethe amakhulu ezinkulungwane noma ngisho nezigidi zamaphikseli. Cabanga nge-pixel njengebhakede elincane elithatha ukukhanya bese liphenduka ibe isignali kagesi.
Indlela i-CMOS & amp; Ama-CCD Sensors ahlukene
Enenzwa yesithombe se-CCD, amaphikseli athatha ukukhanya futhi ayithuthele emaphethelweni we-chip lapho iguqulwa khona ibe yisignali yedijithali. Esikhathini senzwa ye-CMOS, ukukhanya kuguqulwa ku-pixel ngokwayo - akukho ibhande lokuthutha kagesi elidingekayo. Le umehluko ecashile iyabalulekile: ngoba isibonakaliso sokukhanya akudingeki sithunyelwe emaphethelweni we-chip ukuguqulwa, inzwa ye-CMOS idinga amandla angaphansi ukusebenza. Lokhu kusho ukuthi, konke okulinganayo, i-camcorder ene-CMOS inzwa izohlinzeka impilo engcono yebhethri kunomunye we-CCD. Yiqiniso, izinto cishe azifani, ngakho-ke ungacabangi ukuthi i-camcorder ye-CMOS inempilo ebhethri engcono kune-CCD ehlukile.
Iminyaka eminingi, izinzwa ze-CCD zesithombe zacatshangwa ukuthi ubuchwepheshe obuphakeme kakhulu kunomfanekiso nekhwalithi yevidiyo okhathazekile. Kodwa-ke, izinzwa ze-CMOS zenze ukwanda okukhulu kulowo mnyango futhi manje zitholakala kwinani elikhulayo lama-camcorders kuwo wonke amazinga wamanani. U-Sony, njengamanje, usebenzisa i-CMOS inzwa ephezulu ye-line definition yekhamera ye-camcorder, i -HDR-XR520V.
Ngakho-ke, ngenkathi ama-CMOS ne-CCD image sensors ehlukile, akwenzi ngendlela ngendlela okufanele ibe nomthelela kumthengi ojwayelekile. Kufanele ukhokhele kancane uhlobo lwenzwa ku-camcorder yakho futhi uqaphele ngokwengeziwe inani lephikseli nobukhulu bomzimba wenzwa.
I-Pixel Counts
Uma ubukeza ukucaciswa kwekhamera, uzovame ukubona izinombolo ezimbili zezinombolo ezifakwe yinzwa: isibalo esiphezulu se-pixel kanye nokubala kwephikseli ephumelelayo. Inani eliphelele libhekisela kwinani eliphelele lamaphikseli enenzwa, kodwa ngempumelelo ikwazisa ukuthi zingaki amaphikseli azosetshenziswa lapho ethatha ividiyo noma namanje izithombe. Ngakho-ke, unake ukubalwa kwe-pixel esebenzayo uma ufuna isinqumo sevidiyo yakho.
Ukubalwa kwamaphikseli okusebenzayo kubalulekile ngesinye isizathu: kukusiza ukuthi uthathe uhlobo oluthile lokumaketha. Thatha i-Camcorder A. It ithi ingathatha isithombe esingu-10-megapixel (ie isithombe esinamaphikseli ayizigidi ezingu-10 kuso). Kodwa uma ubuka inani lamaphikseli asebenzayo kumzwa wayo wesithombe, ubona kungumqondo we-4-megapixel kuphela. Inzwa yesithombe se-megapixel engu-4 ithatha kanjani isithombe esingu-10-megapixel? Yenziwe ngenqubo ebizwa ngokuthi i-interpolation. Njengomthetho jikelele, kufanele ususe ikhwalithi yezithombe ezakhiwe nge-interpolation. Esikhundleni salokho, sebenzisa inombolo yamaphikseli asebenzayo kunenzwa yekhamera njengesiqondiso sokulungiswa kwangempela kwezithombe zakho.
Ukubaluleka kobukhulu besithombe sesithombe
Inombolo yamaphikseli esithombeni sesithombe akuyona kuphela into ethonya ikhwalithi yevidiyo ethunjiwe. Ubukhulu obungokwenyama wezindaba zensimbi kanye. Izinzwa ezinkulu zesithombe zingathatha ukukhanya okungaphezulu kunezincane, ngisho noma zinamaphikseli ambalwa. Kungenxa yokuthi, ngenkathi kunenani, lezi pixel zinkulu futhi ngaleyo ndlela zikwazi ukuthatha ukukhanya okungaphezulu.
Yingakho uzobona amakhamera amemezela hhayi kuphela inani lamaphikseli esithombeni sesithombe, kodwa ubukhulu bezinzwa ngokwayo (ngokuvamile ezigcawini ze-intshi). Kungcono ukuthenga i-camcorder ngenzwa yesithombe esikhulu nakakhulu noma ngabe kunamaphikseli ambalwa kunomodeli wokuncintisana ngenzwa encane namaphikseli amaningi.