Yuav ua li cas yog lub diaphragm thiab yuav ua li cas tsim muaj feem xyuam rau qhov zoo ntawm cov dluab.

Lub koob yees duab yog invented nyob rau hauv lub twenties ntawm lub thib kaum xya xyoo pua los ntawm Yauxej Niepce. Nws Niépce tswv lub ntiaj teb no tus thawj duab "Saib", ib tug excerpt ntawm uas yog 30 feeb. Txij thaum ntawd los, cov koob yees duab ntawm lub theej txheej thaum ub yooj yim opto-mechanical pab kiag li lawm tau ua sophisticated hluav taws xob uas siv qhov tseeb yees thiab tsim nyob rau hauv yuav luag tag nrho cov teb ntawm science thiab technology. Lub ntsiab hloov tau muaj kev txhawj xeeb rau kev tsim kho, tiam sis, tsis yog txhua txhua qhov chaw ntawm lub koob yees duab. Tej zaum qhov tseem ceeb tshaj plaws thiab kev txiav txim lub tsev ntawm txhua yam ntawm cov koob yees duab - lub lens - tsis tau hloov li ntau li ntau lub thiaj li hu ua lub cev, cov khoom ua si nrog electronics. Suffice nws yuav tau nco ntsoov hais tias cov laus lo ntsiab muag rau zaj duab xis cov koob yees duab thiab tam sim no ua hauj lwm txig rau niaj hnub cov koob yees duab nrog advanced hluav taws xob cov ntsiab lus nyob rau hauv daim ntawv ntawm ib tug matrix ntawm hluav taws xob sensors, actuators rau autofocus thiab lwm yam kev nrhav. Muaj ntau cov kev pab txog txawm xav siv laus lo ntsiab muag, xav tias lawv yuav tsum tau ntawm ntau dua zoo, muab ib tug tshwj xeeb lub povhaum rau koj cov duab.

Lens siv thaum xub thawj siab ib muag tej yam yooj yim thiab unassuming. Nws comprises optics nyob rau hauv daim ntawv ntawm ib tug lens (los yog ntau tshaj lo ntsiab muag yog tag nrho rau hauv ib zuag qhia tag nrho system) ntug uas ua hauj lwm pab raws li lub lens lub cev thiab lub diaphragm.

Lens apparatus nyob ntawm nws lub hom phiaj. Qhov yooj yooj yim yooj yim lo ntsiab muag, txhua yam yog yooj yim. Ob peb lo ntsiab muag nrog ib lub cheeb coj mus rau lub hom lub koob yees duab (tus loj dua cov kab uas hla ntawm lo ntsiab muag, lub ntau dua nws muaj peev xwm thiab aperture piv), lub diaphragm thiab lub vaj tse ib ncig nrog tsom thiab iris tswj thiab fastening mechanism coj mus rau cov koob yees duab lub cev.

Nyob rau hauv zoom lo ntsiab muag mus rau qhov txheej ntsiab ntxiv kuj zoom mechanism.

Ntawm cov hoob kawm, qhov zoo ntawm lub lens yog txiav txim los ntawm dab tsi optics mounted rau nws. Los ntawm cov lens khoom nyob rau hauv lub xub ntiag los yog tsis tuaj kawm ntawv ntawm distortion ntawm lawv txoj kab uas hla - cov neeg kawm ntawv ntawm vignetting, piv txwv li lub darkening ntawm cov npoo ntawm cov ncej, aberrations thiab lwm yam kev txawv txav.

Tsis muaj tsawg ib qho tseem ceeb ib feem ntawm lub lens yog nws aperture.

Yuav ua li cas yog lub diaphragm? Qhov no lens caij uas tsom kwm cov nqi ntawm lub teeb uas nkag mus rau los ntawm lub lens mus rau lub matrix los yog zaj duab xis.

Lub diaphragm muaj ib tug thiaj li hu ua lobe thiab txhais tsis xws li lub qhov tob ntawm daim teb thiab bokeh daim ntawv. Thiab yog hais tias cov nqe lus nug yog, dab tsi yog qhov diaphragm, no mas, tej yam yooj yim, nws tsis yog txhua leej txhua tus paub li cas ib tug bokeh thiab qhov tob ntawm daim teb mas, ib tug yam ntxwv ntawm high-zoo duab.

Yog li ntawd, bokeh. Lub diaphragm muaj lobes uas ntws los sib tshuam, kom txhob muaj cov qhib thiab diverge, ua nws. Bokeh txiav txim los ntawm tus xov tooj ntawm cov tib lobe: Qhov ntau, cov zoo bokeh, uas yog tus ntau lawm daim ntawv no yog zim zuag unfocused.

Realizing hais tias xws li ib tug diaphragm, koj yuav mus rau ib tug tob ntawm daim teb. Nws yog loj, tus me tus aperture qhib. Rau scenery shooting feem ntau yog siv me me aperture qhib rau muaj ntau dua kom meej, tab sis rau portraiture zoo haum loj aperture qhov, uas tso cai rau kom mloog zoo kom pom tseeb rau ib tug kawm thiab yuav tsum tsis txhob ruaj tom qab kev nthuav dav.

Yog li ntawd, peb tau txiav txim siab hais tias qhov no aperture, bokeh thiab tob ntawm daim teb, tab sis kuj nyob rau hauv nqe lus dav dav, yuav ua li cas lub koob yees duab thiab dab tsi lens tsim. Cov ntaub ntawv no yog purely exploratory nyob rau hauv cov xwm, tab sis lawv tseem ceeb heev rau novice kev pab txog, raws li yog lub hauv paus rau qhov kev nkag siab ntawm cov kev nta ntawm lub koob yees duab, uas nyob rau hauv peb hnub ib tug ntau, thiab yog tsim los ntawm leaps thiab ciam teb ntawm lub universalization thiab piv cov txheej txheem ntawm shooting. Nws tseem raug nyob tsuas mus xaiv tus zoo haum lub koob yees duab thiab pib tsim koj tus kheej masterpieces ntawm photographic kos duab. Nws yog yooj yim li thiab thiaj li txias!