Qonda ukuhluka phakathi kwama-CMOS ne-CCD Sensors
Zonke amakhamera zedijithali unenzwa yesithombe esithatha ulwazi ukudala isithombe. Kunezinhlobo ezimbili eziyinhloko zamapenseli wesithombe-i-CMOS ne-CCD-futhi ngayinye inezinzuzo zayo.
Isizwa Sithombe Sisebenza Kanjani?
Indlela elula yokuqonda inzwa yesithombe ukucabanga ngakho njengengxenye yefilimu. Uma inkinobho ye-shutter ikhamera yedijithali igxilile, ukukhanya kufaka ikhamera. Isithombe sitholwe kwi-sensor ngendlela efanayo ukuthi izodalulwa kwisiqephu sefilimu ku-35mm ikhamera yefilimu.
Izinzwa zekhamera zedijithali ziqukethe amaphikseli aqoqa ama-photons (amaphakethe amandla okukhanya) aguqulwa abe yi-electrical charge nge-photodiode. Futhi, lolu lwazi luguqulwa libe yinani ledijithali ngomguquli we- analog-to-digital (ADC) , okuvumela ikhamera ukuthi isebenze amanani kumfanekiso wokugcina .
Amakhamera we-DSLR namakhemikhali okukhomba-nokudubula ngokuyinhloko asebenzisa izinhlobo ezimbili zezitho zithombe: i- CMOS ne-CCD.
Kuyini umbukeli wezithombe zeCDC?
Izinzwa ze-CCD (I-Charge Coupled Device) ziguqula izilinganiso ze-pixel ngokulandelana ngokusebenzisa izigaba ezizungezile inzwa. Ama-CCD asebenzisa i-amplifier eyodwa kuwo wonke amaphikseli.
I-CCDs yenziwa ema-foundries anezixhobo ezikhethekile. Lokhu kubonakala ezindleko zabo ezivame ukukhuphuka.
Kunezinzuzo ezithile ezihlukile kwi-CCD sensor ngaphezu kwenzwa ye-CMOS:
- Umsindo ongaphansi kanye nezithombe eziphakeme kakhulu, ikakhulukazi ezimweni eziphansi
- Ukujula kombala okungcono ngoba ububanzi obunamandla bensizi kaningi kabili kwezinzwa ze-CMOS
- Ukulungiswa okuphakeme nokuzwela okulula
Iyini Isithombisi Somsindo we-CMOS?
Izinzwa ze-CMOS (Complementary Metal Oxide Semiconductor) ziguqula izilinganiso zamaphikseli kanyekanye, zisebenzisa isisindo ngokwayo. Izinzwa ze-CMOS zisebenzisa ama-amplifier ahlukile kumaphikseli ngayinye.
Izinzwa ze-CMOS zivame ukusetshenziswa ku-DSLRs ngoba zishesha futhi zishibhile kunama-CCD sensors. Kokubili i-Nikon ne-Canon zisebenzisa izinzwa ze-CMOS kumakhamera azo aphezulu e-DSLR.
Inzwa ye-CMOS inezinzuzo zayo:
- Isivinini sokucubungula ngokushesha ngoba amaphikseli asebenzayo ne-ADC asezingeni elifanayo
- Ukusebenzisa amandla okuphansi, okungenani izikhathi eziyi-100 ngaphansi kwe-CCD
- Imisebenzi yekhamera edidiyelwe ifana nokwehliswa kwezimoto, ukufaka ikhodi encoding, nokucindezela kwesithombe ngqo ku-chip
- Ivimbela "ukukhahlela" uma isithombe siphelelwe yisikhathi
- Inqubo yokukhiqiza eyabizayo, efana neyayiphi i-microprocessor, yenza ibe yabiza kakhulu
- Ikhwalithi ithuthuke kakhulu kusukela ekusungulweni kwayo
Izihlungi Zemibala Yesihlungi Semibala
Umbala wokuhlunga umbala ufakwe phezulu kwensimu ukuthatha izingxenye ezibomvu, eziluhlaza, neziluhlaza okwesibhakabhaka esiwela enzwa. Ngakho-ke, i-pixel ngayinye ikwazi ukukala umbala owodwa kuphela. Leminye imibala emibili kulinganiswa yisensela esekelwe amaphikseli azungezile.
Ngenkathi lokhu kungathinta ikhwalithi yesithombe kancane, akubonakali nakancane kumakhamera aphezulu okulungisa. I- DSLRs eminingi yamanje isebenzisa lobu buchwepheshe.
I-Foveon Sensors
Amehlo abantu abhekene nemibala emithathu eyisisekelo yobomvu, obuluhlaza, nobuluhlaza, neminye imibala eyenziwa yinhlanganisela yemibala eyinhloko. Kwifilimu yezithombe, imibala ehlukene eyinhloko iveza ungqimba oluhambisana nalo lwefilimu.
Ngokufanayo, izinzwa ze-Foveon zinezendlalelo ezintathu zenzwa, ngasinye esilinganisela enye yemibala eyinhloko. Isithombe sikhiqizwa ngokuhlanganisa lezi zendatshana ezintathu ukukhiqiza imidwebo yamatayela aphakathi. Lokhu kusekhona ubuchwepheshe obusha obusetshenziswa kwamanye amakhamera we-Sigma.