Auto Focus vs Fixed Focus
Kev ua kom pom tseeb thiab ua kom pom tseeb yog ob qho tseem ceeb heev uas tau tham hauv kev yees duab. Ob lo lus no feem ntau yog txhais tsis raug, thiab yuav tsum muaj kev qhia meej meej ntawm ob lub ntsiab lus no. Kab lus no yuav sim piav qhia seb nws pib ua kom pom tseeb thiab qhov ua kom pom tseeb yog dab tsi, lawv qhov zoo sib xws thiab thaum kawg lawv qhov sib txawv.
Auto Focus
Yuav kom nkag siab lub tswv yim ntawm autofocus, lub tswv yim ntawm kev ua kom pom tseeb yuav tsum nkag siab ua ntej. Daim duab tsom yog qhov ntse tshaj plaws. Hauv kev nkag siab ntawm optics, lub teeb los ntawm qhov "tsim" taw tes ua rau cov duab ntawm lub sensor, thaum lub teeb los ntawm qhov tsis pom kev yuav ua rau cov duab tom qab lossis pem hauv ntej ntawm lub sensor. DSLR koob yees duab thaum muaj hnub nyoog ntxov yog phau ntawv tsom xam. Kev tsom xam ntawm ib feem ntawm cov duab lossis tag nrho cov duab tau ua tiav manually los ntawm kev tig lub nplhaib tsom rau ntawm lub lens raj. Raws li cov koob yees duab digital pib tawm, cov tshuab autofocusing kuj tau tsim. Lub kaw lus autofocusing yog ib qho system uas lub lo ntsiab muag tau txav mus los txhawm rau txhawm rau txhawm rau pom qhov xav tau lossis thaj tsam ntawm daim duab. Nws pib ua kom pom tseeb yog qhov tseem ceeb heev hauv DSLR niaj hnub no, taw tes thiab tua thiab txawm tias lub koob yees duab xov tooj ntawm tes. Ib qho tshwj xeeb tseem ceeb ntawm kev tsom xam yog qhov tob ntawm qhov chaw. Nws txhais tau hais tias ntau npaum li cas ntawm daim duab yog tsom rau pem hauv ntej thiab tom qab cov khoom tsom. Nws tseem yuav tsum tau muab sau tseg tias txhua yam khoom ntawm tib lub dav hlau nrog rau qhov taw tes los ntawm lub koob yees duab yuav raug tsom.
Fixed Focus
Fixed focus system yog lub lens system uas qhov kev ncua deb ntawm lo ntsiab muag tsis tu ncua. Nyob rau hauv lwm yam lus, ib tug taag focus system muaj ib tug taag lens teeb. Raws li tau hais ua ntej, qhov tob ntawm thaj teb yog qhov cuam tshuam tseem ceeb ntawm kev tsom. Xav txog qhov taw tes thiab tua lub koob yees duab nrog lub hom phiaj ruaj khov. Yog tias qhov tob ntawm thaj teb tsawg heev, (piv txwv li thaj chaw tom qab thiab nyob rau hauv pem hauv ntej ntawm qhov chaw tsom mus rau qhov muag plooj), lub koob yees duab yuav pab tau tsuas yog rau qhov ntev ntawm qhov khoom. Thiab ob qho tib si keeb kwm yav dhau thiab foreground tsis tuaj yeem tsom mus ib txhij. Qhov tob ntawm qhov chaw nyob ntawm ntau yam. Ib qho yog qhov aperture ntawm lub lens. Yog hais tias lub aperture loj, qhov tob ntawm daim teb yuav me me. Tib yam mus rau qhov chaw zoom. Tab sis yog tias lub ntsiab lus tseem ceeb nyob deb, D. O. F. yuav siab dua. Yog li ntawd, cov koob yees duab ua kom pom tseeb ruaj khov tau ua rau tsom mus rau qhov tsis muaj tseeb nrog cov apertures me me thiab cov chaw zoom me me. Qhov no yuav tso cai rau lub koob yees duab tsom mus rau yuav luag txhua yam khoom hauv daim teb.
Theem "auto focus" yog qee zaum siv rau hauv cov ntsiab lus ntawm "taw focused", txij li tag nrho cov khoom "automatically tau focused" nyob rau hauv ib tug ruaj focused lub koob yees duab. Txawm li cas los xij, qhov no yog kev xav tsis zoo, thiab tsis muaj automation lossis mechanical txheej txheem koom nrog hauv kev tsom mus rau qhov system.
Dab tsi yog qhov txawv ntawm Auto Focus thiab Fixed Focus?
• Autofocus xav tau qee qhov kev txav mus los los kho cov lo ntsiab muag kom pom cov khoom xav tau, tab sis lub kaw lus tsom iav tsis txav mus.
• Lub kaw lus ua kom pom tseeb yog ib txwm tsom mus rau qhov kawg, tab sis qhov kev ua kom pom tseeb nws tus kheej tuaj yeem tsom mus rau qhov deb li ntawm zero mus rau infinity.
