Lub Koob Yees Duab Digital HDR Video Recording
Kev tsim cov koob yees duab digital hauv kaum xyoo dhau los no tau cim tsis yog los ntawm kev daws teeb meem ntau dua xwb tab sis kuj los ntawm lub peev xwm los ntes tau ntau yam dynamic. Qhov no yog qhov uas lub tswv yim ntawm HDR (High Dynamic Range) ua qhov tseem ceeb. Thaum HDR tau paub dua hauv ntiaj teb kev thaij duab, tam sim no nws tau tshwm sim ntau dua hauv kev kaw video - ntawm cov koob yees duab mirrorless, DSLRs niaj hnub no, cov koob yees duab digital xinesmas, thiab txawm tias smartphones. Tsab xov xwm no tham txog HDR video yog dab tsi, nws ua haujlwm li cas ntawm cov koob yees duab digital, cov hom ntawv siv feem ntau, thiab cov lus qhia tswv yim rau kev tsim cov ntaub ntawv HDR zoo.
HDR Video Yog Dab Tsi?
Hais yooj yim xwb, HDR yog lub peev xwm ntawm lub koob yees duab los ntes cov ntsiab lus tib lub sijhawm hauv thaj chaw ci ntsa iab thiab thaj chaw tsaus ntuj heev. Hauv cov xwm txheej muaj kev sib piv siab - piv txwv li, lub ntsej muag ntawm ib tus neeg hauv tsev nrog lub qhov rais ci ntsa iab tom qab lawv - cov yeeb yaj kiab ib txwm muaj feem ntau "tsis zoo": lub ntsej muag tsaus dhau lossis lub qhov rais dawb thiab tsis muaj cov ntsiab lus (overexposed). Cov yeeb yaj kiab HDR lub hom phiaj yog khaws cov ntsiab lus hauv ob qho tib si.
Tab sis HDR tsis yog hais txog "cov duab ci dua xwb." HDR yog kev sib xyaw ua ke ntawm ntau yam dynamic, qhov tob ntawm qhov me me, thiab qhov nkhaus hloov pauv, lossis txoj kev encoding luminance, uas tso cai rau kev kaw zoo dua thiab tso saib cov ntaub ntawv tsaus ntuj.
Vim li cas HDR thiaj tseem ceeb hauv kev yees duab?
Cov yeeb yaj kiab txawv ntawm cov duab vim nws muaj cov thav duab txav mus los. Qhov kev sib tw: kev hloov lub teeb thiab kev txav ntawm cov ntsiab lus ua rau cov txheej txheem HDR (piv txwv li, kev sib xyaw ntau qhov kev nthuav tawm) nyuaj. Txawm li cas los xij, qhov kev thov rau HDR hauv cov yeeb yaj kiab tab tom loj hlob vim tias:
1. Kev faib cov ntsiab lus niaj hnub no: Ntau lub TV thiab cov kev pabcuam streaming txhawb nqa HDR.
2. Zoo li zaj duab xis: HDR muab kev ywj pheej ntau dua thaum hloov xim.
3. Cov xwm txheej sib txawv siab: Cov ntaub ntawv, cov xwm txheej, thiab kev npog sab nraum zoov feem ntau ntsib teeb pom kev zoo heev.
Yuav ua li cas cov koob yees duab digital kaw HDR
Muaj ntau txoj hauv kev uas cov koob yees duab digital siv los tsim cov yeeb yaj kiab HDR:
1. Lub Sensor Dynamic Range Siab
Cov koob yees duab niaj hnub nim no muaj cov sensors uas muaj peev xwm ntes tau qhov dynamic range dav dua, piv txwv li, 12–15 stops lossis ntau dua ntawm cov koob yees duab qib xinesmas. Qhov siab dua ntawm qhov sensor's dynamic range, qhov yooj yim dua los ntes cov duab ntxoov ntxoo yam tsis tau ua rau cov highlights ploj sai.
2. Cov Ntaub Ntawv Teev (Log Gamma)
Muaj ntau lub koob yees duab muaj cov profile xws li S-Log (Sony), C-Log (Canon), V-Log (Panasonic), N-Log (Nikon), lossis Log dav dav. Kev kaw cov cav tsis zoo li "zoo" tam sim ntawd vim nws zoo li tiaj tus, tab sis nws khaws cov ntaub ntawv ntau dua rau kev ua thaum lub sijhawm ntsuas.
Cov txiaj ntsig ntawm cov cav:
- Cov ntsiab lus tseem ceeb muaj kev nyab xeeb dua.
- Cov duab ntxoov ntxoo yooj yim dua rau tshem tawm thaum lub sijhawm kho.
- Muaj kev ywj pheej ntau dua rau kev hloov xim.
Cov kev tsis zoo:
- Yuav tsum muaj cov txheej txheem tom qab tsim khoom.
- Qhov zoo tshaj plaws, siv qhov tob ntawm qhov tob (10-bit) kom tiv thaiv kev yooj yim banding.
3. HLG (Hybrid Log Gamma)
HLG yog tsim los kom cov ntsiab lus HDR tso tawm tau zoo ntawm cov zaub HDR, thaum tseem sib xws thaum tso tawm ntawm cov zaub SDR. HLG feem ntau yog qhov kev xaiv zoo rau kev tsim khoom sai, kev tshaj tawm cov xwm txheej, lossis cov kev xav tau uas tsis xav tau kev ntsuas qib nyuaj.
4. PQ (Kev Ntsuas Qhov Ntsuas) / HDR10
HDR10 feem ntau siv cov kab PQ nrog cov metadata tshwj xeeb. Qee lub koob yees duab lossis cov txheej txheem ua haujlwm tuaj yeem coj cov ntaub ntawv kaw rau HDR10 mastering. Qhov no yog ib txwm muaj nyob rau hauv cov khoom tsim tawm uas ua raws li cov qauv streaming lossis kev faib tawm tshaj tawm tshwj xeeb.
5. Kev Tawm Ntau Yam / Ob Chav Tau Txais Tawm (DGO)
Qee lub koob yees duab siv cov thev naus laus zis xws li Dual Native ISO, Dual Gain Output, lossis cov txheej txheem nyeem ntawv sensor uas ua kom pom tseeb thiab pom tseeb. Kuj tseem muaj cov txheej txheem uas muab ntau qhov kev nthuav dav hauv video, txawm hais tias kev siv sib txawv thiab qee zaum txwv rau qee yam xwm txheej.
Qhov tob ntawm qhov Bit thiab Codecs: Lub hauv paus ntawm HDR Recording
Cov khoom uas feem ntau txiav txim siab seb koj qhov HDR puas "huv" lossis puv ntawm cov khoom cuav yog qhov tob thiab codec.
– 8-ntsis: Muaj kev cuam tshuam ntau dua thaum lub sijhawm ua kom zoo dua qub. Tseem ua tau rau HDR me me, tab sis muaj kev txwv.
– 10-ntsis: Feem ntau suav tias yog qhov tsawg kawg nkaus zoo tagnrho rau HDR vim nws khaws cov xim du thiab du.
– 12-ntsis / RAW: Muab kev ywj pheej siab tshaj plaws, tshwj xeeb tshaj yog rau kev tsim khoom tshaj lij.
Cov codecs kuj muaj qhov cuam tshuam:
– H.264/H.265 (HEVC): Zoo rau qhov loj ntawm cov ntaub ntawv, siv dav los ntawm cov koob yees duab thiab xov tooj ntawm tes.
– ProRes / DNx: Loj dua, tab sis yooj yim dua rau kev hloov kho thiab ruaj khov rau kev tsim khoom tom qab.
- RAW video: Cov ntaub ntawv "raw" tshaj plaws, hloov pauv tau, tab sis hnyav hauv kev khaws cia thiab kho kom raug.
Rau HDR, ntau tus neeg tsim khoom xaiv 10-ntsis nrog lub codec ruaj khov, tshwj xeeb tshaj yog tias lawv yuav ua qib.
Cov Chaw Teeb tsa Lub Koob Yees Duab Uas Cuam Tshuam Rau HDR
Yuav kom ua tiav cov txiaj ntsig HDR zoo tshaj plaws, yuav tsum xav txog ntau yam kev txawj ntse:
1. Kev raug tshuaj
Hauv HDR, kev khaws cov xim ci feem ntau yog qhov tseem ceeb. Ntau tus kws thaij duab siv cov txheej txheem ntawm "kev nthuav tawm los tiv thaiv cov xim ci" los tiv thaiv kev poob ntawm cov ntsiab lus hauv cov chaw ci. Hauv cov ntaub ntawv, cov xim ci uas raug cua tshuab feem ntau nyuaj rau rov qab tau.
Siv cov cuab yeej:
– Histogram
- Waveform
- Qauv zebra
- Xim cuav (yog tias muaj)
2. Kev Sib Npaug Dawb Sib Xws
HDR ua rau pom qhov sib txawv ntawm cov xim ntau dua. Qhov sib npaug dawb uas tsis sib npaug yuav ua rau qib nyuaj. Thaum twg ua tau, siv Kelvin ntawm tes, tsis yog siv auto, tshwj xeeb tshaj yog nyob rau hauv cov xwm txheej uas muaj kev hloov pauv teeb pom kev sib xyaw.
3. ISO thiab Suab Nrov hauv Duab Ntxoo
HDR feem ntau ntxias kom tib neeg muab duab ntxoov ntxoo tso rau ntau dhau. Yog tias ISO siab dhau, suab nrov yuav tshwm sim ntau dua. Xaiv qhov ISO zoo tshaj plaws (feem ntau hu ua ISO yooj yim rau log) kom tau cov duab ntxoov ntxoo huv dua.
4. Kev Tswj Teeb thiab Kev Sib Piv
HDR tsis yog ib yam khoom siv hloov lub teeb. Yog tias qhov sib piv ntau dhau, tseem muaj qhov txwv ntawm lub sensor. Siv lub reflector, lub teeb puv, lossis ND lim kom sib npaug ntawm qhov chaw.
HDR Kev Ua Haujlwm Tom Qab Tsim Khoom
Kev kaw HDR tsuas yog ib nrab ntawm kev sib ntaus sib tua xwb. Yuav kom ua tiav cov txiaj ntsig xav tau, kev ua haujlwm tom qab tsim khoom kuj tseem ceeb heev:
1. Hloov Log mus rau tus qauv tso saib: Feem ntau siv lub Hoobkas LUT lossis kev hloov pauv xim (piv txwv li ACES lossis DaVinci YRGB Xim Tswj).
2. Kev kho xim: Kho qhov sib piv, qhov saturation, highlight roll-off, thiab cov duab ntxoov ntxoo.
3. Kev Tswj: Txheeb xyuas qhov tso zis SDR lossis HDR (HLG/PQ), thiab teeb tsa cov kev teeb tsa raws li lub platform.
4. Kev saib xyuas kom zoo: Qhov zoo tshaj plaws, kev ntsuas HDR yuav tsum tau ua rau ntawm lub monitor HDR uas tau calibrated lawm. Txwv tsis pub, muaj kev pheej hmoo ntawm cov txiaj ntsig sib txawv thaum ua si ntawm HDR TV.
Ntau tus neeg tsim khoom kuj tsim ob hom: HDR rau cov khoom siv sib xws thiab SDR rau kev sib xws dav dav.
Cov Teeb Meem thiab Yuam Kev Feem Ntau
Qee qhov teeb meem uas feem ntau tshwm sim nrog cov yeeb yaj kiab HDR:
- Kev sib tshooj ntawm lub ntuj lossis phab ntsa gradation vim yog 8-bit lossis over-grading.
- Kev txiav cov ntsiab lus tseem ceeb vim yog overexposure.
- Cov xim tawv nqaij zoo li tsis zoo li qub vim yog kev tswj xim tsis raug.
- Qhov screen "ci ntsa iab" dhau lawm vim yog kev nkag siab yuam kev txog HDR - HDR tsis tau txhais hais tias txhua yam yuav ci ntsa iab heev.
- HDR metadata yuam kev ntawm kev xa tawm, uas ua rau muaj kev tso saib txawv txawv ntawm qee cov khoom siv.
Cov Lus Qhia Siv Tau Rau Kev Kaw HDR Video
Nov yog qee cov tswv yim luv luv uas siv tau:
1. Sau tsawg kawg yog 10-bit yog tias ua tau.
2. Xaiv qhov Log profile rau qib kev ywj pheej lossis HLG rau kev ua haujlwm sai.
3. Siv lub lim ND thaum nws ci kom lub shutter thiab qhov aperture zoo tagnrho.
4. Saib xyuas qhov kev raug ntawm lub teeb los ntawm waveform/zebra, tsis yog tsuas yog lub vijtsam LCD xwb.
5. Xauv qhov sib npaug dawb rau qhov sib xws.
6. Tsis txhob pleev xim ntau dhau; ua kom nws zoo li ntuj.
7. Xyuas kom tseeb tias cov txheej txheem xa tawm yog raws li lub hom phiaj: SDR, HLG, lossis PQ/HDR10.
Kev kaw
Kev kaw cov yeeb yaj kiab HDR ntawm cov koob yees duab digital qhib cov cib fim zoo kawg nkaus rau kev tsim cov duab zoo nkauj dua, muaj ntau yam ntsiab lus uas npaj rau cov qauv tshaj tawm niaj hnub no. Txawm li cas los xij, HDR kuj xav tau kev nkag siab tob dua txog kev siv tshuab, txij li cov duab profile thiab qhov tob ntawm lub ntsis mus rau cov txheej txheem tom qab tsim khoom. Nrog rau qhov chaw teeb tsa zoo, kev tswj hwm kev pom zoo, thiab kev tswj xim kom zoo, HDR tuaj yeem yog ib qho cuab yeej muaj zog - tsis yog tsuas yog ib qho feature - rau kev txhim kho qhov zoo ntawm koj cov haujlwm video.
Yog tias koj xav tau, kuv tuaj yeem kho cov ntawv no rau ib qho ntsiab lus tshwj xeeb (piv txwv li, tshwj xeeb rau lub koob yees duab tsis muaj iav, tshwj xeeb rau xov tooj ntawm tes, lossis tsom mus rau DaVinci Resolve / Premiere workflow), lossis ntxiv ib ntu nrog cov lus qhia teeb tsa HDR rau cov hom koob yees duab tshwj xeeb.
