Lub Koob Yees Duab Digital Telephoto Lens
Hauv ntiaj teb kev thaij duab digital, lub lens yog "lub qhov muag" uas txiav txim siab seb lub sijhawm yuav raug thaij li cas. Ntawm ntau hom lens, telephoto lenses tuav qhov chaw tshwj xeeb vim lawv muaj peev xwm coj cov neeg nyob deb los ze dua, ua kom pom tseeb, thiab tsim cov yam ntxwv pom tshwj xeeb. Rau ntau tus kws thaij duab - ob tus pib tshiab thiab cov kws tshaj lij - telephoto lenses yog qhov kev xaiv tseem ceeb rau kev thaij duab kis las, tsiaj qus, kev hais kwv txhiaj, thiab txawm tias cov duab nrog cov keeb kwm yav dhau los zoo nkauj. Tsab xov xwm no tham txog lub lens telephoto yog dab tsi, nws ua haujlwm li cas, nws qhov zoo thiab qhov tsis zoo, thiab cov lus qhia rau kev xaiv thiab siv ib qho ntawm lub koob yees duab digital.
Lub Lens Telephoto yog dab tsi?
Lub lens telephoto yog lub lens uas muaj qhov ntev focal ntev dua li lub lens txheem. Feem ntau, ntawm lub koob yees duab full-frame, cov lens telephoto feem ntau pib ntawm kwv yees li 70mm thiab siab dua. Ntawm lub koob yees duab APS-C, vim yog qhov crop factor (piv txwv li, 1,5x lossis 1,6x), txawm tias lub lens 50mm tuaj yeem zoo li "telephoto" ntau dua li lub lens full-frame, tab sis pawg telephoto feem ntau tseem hais txog ntau yam ntawm 55–200mm (nruab nrab-telephoto) txog 300mm thiab siab dua (super telephoto).
Yog tias lub focal length ntev dua ces yuav ua rau lub kaum pom nqaim dua. Lub kaum pom nqaim no ua rau tus neeg uas koj thaij duab zoo li loj dua hauv daim duab, zoo li koj "mus ze dua" yam tsis tau mus ze dua.
Cov Lens Telephoto Ua Haujlwm Li Cas thiab Lawv Cov Yam Ntxim Saib
Lub koob yees duab telephoto tsis yog hais txog "zooming xwb." Muaj cov yam ntxwv pom uas cov kws thaij duab feem ntau nyiam txog nws:
1. Kev nias lub zeem muag
Cov tsom iav telephoto feem ntau ua rau qhov deb ntawm cov khoom pem hauv ntej thiab tom qab zoo li luv dua. Yog li ntawd, keeb kwm yav dhau zoo li "nyob ze dua" thiab feem ntau zoo li loj dua. Qhov cuam tshuam no tshwj xeeb tshaj yog nyiam cov duab toj roob hauv pes nrog cov txheej roob, lossis cov nroog uas muaj cov tsev sib nrug ze.
2. Kev cais cov neeg mob
Vim nws lub kaum sab xis nqaim thiab feem ntau siv los ntawm qhov deb dua, telephoto ua rau nws yooj yim dua rau tus kws thaij duab cais cov khoom ntawm nws ib puag ncig. Cov khoom muaj zog dua, thiab cov khoom ib puag ncig yooj yim dua kom tsis txhob muaj kev cuam tshuam.
3. Bokeh muaj zog dua
Yog tias lub qhov (aperture) loj (piv txwv li, f/2.8 lossis f/4) thiab qhov ntev ntawm lub lens (focal length) ntev, ces qhov keeb kwm yav dhau yuav ua rau pom tsis meej. Qhov no feem ntau siv rau hauv cov duab neeg, cov duab zam, lossis cov duab khoom uas tsom mus rau cov ntsiab lus.
Hom Lenses Telephoto
Qhov tseeb, telephoto tuaj yeem muab faib ua ntau pawg:
- Nruab nrab telephoto (kwv yees li 70-200mm)
Qhov no yog ib qho koob yees duab nrov vim nws muaj ntau yam siv tau: haum rau kev thaij duab neeg, kev tshwm sim, kev thaij duab ncaj ncees, thiab txawm tias kev ua kis las me me. Lub lens 70–200mm f/2.8 feem ntau hu ua "lub zog ua haujlwm ntawm tus kws thaij duab."
– Telephoto ntev (kwv yees li 100–400mm)
Haum rau cov tsiaj qus, kev ua si sab nraum zoov, lossis kev ua ub ua no ntev, cov iav no feem ntau muaj cov qauv zoom 100–400mm lossis 150–600mm.
- Super telephoto (400mm thiab siab dua)
Siv rau kev saib noog, kev mus ncig xyuas safaris, kev ua kis las tshaj lij, thiab kev thaij duab ntev heev, cov iav no feem ntau loj, hnyav, thiab kim, tab sis lawv xa cov txiaj ntsig uas nyuaj rau yeej.
Ntxiv rau qhov ntev ntawm lub lens, cov lens telephoto kuj tseem tuaj yeem muab faib ua prime (fixed focus, piv txwv li, 135mm, 200mm, 300mm) thiab zoom (piv txwv li, 70–200mm, 100–400mm). Cov lens prime feem ntau muab cov lens ntse dua thiab qhov loj dua, thaum cov lens zoom zoom zoom zoom.
Cov txiaj ntsig ntawm Telephoto Lenses
1. ncav cuag cov neeg nyob deb
Qhov no yog qhov zoo tshaj plaws. Koj tuaj yeem thaij duab cov neeg ncaws pob hauv thaj teb, cov noog nyob hauv cov ceg siab, lossis cov neeg hu nkauj lub ntsej muag ntawm theem yam tsis tas yuav nyob ze.
2. Ua kom cov duab portrait zoo nkauj dua
Cov iav tsom iav nruab nrab xws li 85mm, 105mm, lossis 135mm feem ntau siv rau kev thaij duab vim tias lawv txo qhov kev cuam tshuam ntawm lub ntsej muag uas feem ntau pom nrog cov iav tsom iav dav. Lub qhov ntswg tsis zoo li "loj dua," thiab qhov sib piv ntawm lub ntsej muag zoo li ntuj dua.
3. Ua kom yooj yim dua rau kev sau ntawv
Yog tias koj muaj lub kaum sab xis nqaim, koj tuaj yeem "tshem tawm" cov ntsiab lus uas cuam tshuam. Cov kws thaij duab txoj kev thiab cov ntaub ntawv feem ntau siv telephoto rau cov duab ncaj ncees los ntawm qhov deb uas muaj kev nyab xeeb.
4. Pab tsim kom muaj keeb kwm yav dhau mos mos
Nrog kev sib xyaw ua ke ntawm qhov ntev focal thiab qhov aperture dav, qhov tom qab blur effect (bokeh) tuaj yeem yog qhov zoo nkauj tseem ceeb uas ua rau cov duab zoo li kev tshaj lij.
Cov Teeb Meem thiab Cov Kev Tsis Zoo ntawm Telephoto
1. Lub koob yees duab co pom tseeb dua
Qhov ntev ntawm qhov focal ntev npaum li cas, qhov ntau dua uas cov duab yuav tsis meej vim yog kev sib tsoo tes. Yog li ntawd, cov koob yees duab telephoto feem ntau xav tau qhov ceev ntawm lub shutter, kev ruaj khov (OIS / IS / VR), lossis tripod / monopod.
2. Loj thiab qhov hnyav
Cov tsom iav Telephoto, tshwj xeeb tshaj yog cov uas muaj qhov loj, feem ntau loj thiab hnyav. Qhov no cuam tshuam rau kev xis nyob, kev txav mus los, thiab qhov xav tau lub hnab nqa lub koob yees duab.
3. Cov nqi siab dua
Cov tsom iav telephoto zoo—tshwj xeeb yog f/2.8 lossis super telephoto—feem ntau kim vim yog cov qauv tsim kho qhov muag nyuaj thiab siv cov khoom siv tshwj xeeb.
4. Cov kev xav tau lub teeb ntau dua
Ntau lub lens telephoto rau cov neeg siv khoom muaj qhov qhib tau ntau yam xws li f/4.5–6.3. Thaum muaj teeb pom kev tsawg, koj yuav raug yuam kom nce ISO lossis txo qhov ceev ntawm lub shutter, uas ua rau muaj kev pheej hmoo ntawm suab nrov lossis qhov tsis meej.
Cov Lus Qhia rau Kev Xaiv Lub Lens Telephoto rau Lub Koob Yees Duab Digital
1. Kho kom haum rau koj cov kev xav tau thaij duab
– Duab thiab tej xwm txheej: 70–200mm lossis 85–135mm prime.
- Kev ua si sab nraum zoov: 100–400mm lossis 70–200mm nrog lub cev qoob loo.
– Cov tsiaj qus/noog: 300mm thiab siab dua, zoo dua yog 400–600mm.
2. Xav txog lub koob yees duab sensor (full-frame vs APS-C/MFT)
Qhov crop factor ua rau lub lens zoo li ntev dua. Lub lens 200mm ntawm 1,5x APS-C zoo li lub lens 300mm ntawm full-frame.
3. Kev ruaj khov duab yog qhov pab tau heev
Yog koj feem ntau thaij duab thaum koj siv tes tuav, xaiv lub lens uas muaj optical stabilization. Qhov no tsis yog ib yam khoom siv hloov qhov ceev ntawm lub shutter ceev rau cov khoom uas txav mus los, tab sis nws pab tau zoo heev rau cov khoom uas tsis txav.
4. Lub qhov ntawm lub lens: f/2.8, f/4, lossis f/5.6?
- f/2.8 zoo heev hauv lub teeb tsawg thiab bokeh, tab sis nws hnyav thiab kim.
- f/4 sib dua thiab feem ntau tseem ntse.
– f/5.6–6.3 pheej yig dua, tsim nyog rau kev siv sab nraum zoov kaj.
5. Tshawb xyuas qhov ntse thiab kev ua tau zoo ntawm autofocus
Cov tsom iav telephoto feem ntau siv rau kev ua haujlwm sai. Kev tsom mus rau qhov tseem ceeb thiab teb tau zoo, tshwj xeeb tshaj yog rau kev ua kis las thiab tsiaj qus.
Cov Txheej Txheem Siv Telephoto Rau Qhov Zoo Tshaj Plaws
- Siv qhov ceev ntawm lub shutter kom muaj kev nyab xeeb
Txoj cai dav dav: 1/(qhov ntev ntawm lub lens) vib nas this kom tsis txhob muaj qhov tsis meej (piv txwv li 1/200 rau 200mm). Rau cov koob yees duab uas muaj kev daws teeb meem siab lossis cov uas tsis muaj kev ruaj khov, feem ntau nws yuav tsum tau ua kom sai dua.
- Siv qhov zoo ntawm hom tawg thiab AF taug qab
Rau cov khoom txav mus los, siv lub autofocus tas mus li thiab kev tua duab tawg kom koj muaj feem tau txais lub sijhawm ntse dua.
- Ua tib zoo saib qhov ntev ntawm lub focal thiab ntau yam kev txav mus los
Telephoto tso cai rau koj thaij duab ntawm qhov deb, tab sis tseem yuav tsum tau ua tib zoo saib qhov chaw sib sau ua ke kom tus neeg ntawd tsis raug "txiav" thiab keeb kwm yav dhau tsis cuam tshuam.
- Siv monopod lossis tripod yog tias tsim nyog
Rau cov iav hnyav lossis cov duab ntev, monopod yog qhov kev pab zoo hauv kev tswj kom ruaj khov yam tsis txo qhov kev txav mus los tag nrho.
Kev kaw
Lub lens telephoto yog qhov kev nqis peev tseem ceeb rau cov kws thaij duab uas tab tom nrhiav kev thaij cov ntsiab lus nyob deb thiab tsim kom muaj kev cuam tshuam zoo rau lub zeem muag - txawm tias los ntawm kev nias lub zeem muag, kev cais cov ntsiab lus, lossis kev nyiam bokeh. Txawm hais tias lawv muaj cov teeb meem xws li qhov xav tau kev ruaj khov, qhov hnyav, thiab tus nqi, cov txiaj ntsig feem ntau tsim nyog, tshwj xeeb tshaj yog rau kev ua kis las, tsiaj qus, theem, thiab kev thaij duab. Los ntawm kev nkag siab txog cov yam ntxwv ntawm lub lens telephoto thiab xaiv qhov ntev focal thiab qhov aperture range, koj tuaj yeem ua kom koj lub koob yees duab digital muaj peev xwm ua kom pom tseeb, ua yeeb yam, thiab cov duab ntxaws ntxaws.
