Valoherkkyys

Tämä elokuvan herkkyys

Tämä elokuvan herkkyystolightiscalledthesensitivityofthefilm.Whentheunexposedfilmencounterslight,achemicalreactionoccursonthefilm.Dependingonhowmuchlightenters,thefilmwillhavedifferentshadesofchangeatdifferentpositions,therebyleavinganimageonthefilm.

Itisworthmentioningthatalthoughitistroublesometoreplacethefilm,inactualshooting,duetovariousconditions,sometimestheuseofhigh-sensitivityfilmwillbecomeanecessarychoice.Sportsphotographersoftenusehigher-sensitivityfilm,becauseiftheydonotuseit,theywillhavetoslowdowntheshutterspeedtoincreasetheamountoflight,whichwillresultinblurryphotosandlossofusefulness.

Light sensitivity

Digikameran herkkyys

Digitalcameradoesnothavenegativefilmandchemicalreactiononnegativefilm.Itssensitivityisanindexsimilartofilmsensitivity.Kindofequivalentsensitivity.Infact,theISOofadigitalcameraisachievedbyadjustingthesensitivityofthephotosensitiveelementtolightormergingthephotosensitivepoints,thatistosay,byimprovingthelightsensitivityofthephotosensitiveelementormergingseveraladjacentpixelstoincreasetheISO.thegoalof.

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Johdanto

WhenconvertingfromthelogarithmicDINsensitivityvalueS°totheexpressionASAThesensitivityvalueSiscalculatedbythefollowingequation:

Thecalculatedresultisroundedtothenearestinteger.Rearrangetheaboveequations,andthereverseconversionequationisasfollows:

Theresultofthesamecalculationisroundedtothenearestinteger.Thebaseofloghereis10.

Virta-asteikkojen vertailu

Thefollowingtableshowsthecomparisonofvarioussensitivityscales:

td>td>
Table1.Comparisonofvariousdifferentsensitivityscales
ISOcalculationscale(ASAscale)ISOlogarithmicscale(DINscale)GOST(Early1987intheSovietUnion)Negativeproductswithcorrespondingsensitivity
1SvemaMicrat-orto,AstrumMicrat-orto
32.8SvemaMZ-3,AstrumMZ-3
6OriginalKodachrome
810°PolaroidPolaBlue
1011°Kodachrome8mmfilm
1212°11Gevacolor8mmreversalfilm
1613°11Agfacolor8mmreversalfilm
2014°16AdoxCMS20
2515°22OldversionAgfacolor,Kodachrome25
3216°22KodakPanatomic-X
4017°32Kodachrome40(movie)
5018°45FujiRVP(Velvia)
6419°45Kodachrome64,Ektachrome-X
8020°65IlfordCommercialOrtho
10021°90KodacolorGold,KodakT-Max(TMX),Provia
12522°90SvemaColor125,AstrumColorNegative125,IlfordFP4+,KodakPlus-XPan
16023°130FujicolorPro160C/S,KodakHigh-Speed​​Ektachrome
20024°180FujicolorSuperia200
25025°180TasmaFoto-250
32026°250KodakTri-XPanProfessional(TXP)
40027°350KodakT-Max(TMY),Tri-X400,IlfordHP5+
50028°350
64029°560Polaroid600
80030°700FujiPro800Z
100031°700KodakP3200TMAX,IlfordDelta3200(seetextbelow)
125032°
160033°1400–1440Fujicolor1600
200034°
250035°
320036°2800–2880KodakT-Max(TMZ)
400037°
500038°
640039°
1280042°
2560045°
5120048°
10240051°

Vanhan mittakaavan muunnos

TheconversionbetweenASAandDINinthe1960sand70swasdifferentfromtoday.Thefigureshowsthescaleconversionin1952.Forexample,DIN21correspondstoASA80insteadofASA100.

ominaisuudet

Thehigherthesensitivityspeed,thelargerthevalue.Inadditiontoshorteningtheexposuretime,italsohasanimpactonimagequality.Generallyspeaking,theimagequalityatlowsensitivityismoredelicateandthecolorsaremorefaithful.Whenthesensitivityishigh,therewillbenoiseandgrainproblems,makingthephotosmoreunbearabletozoomin.Whetheritisfilminthepastordigitalcamerastoday,thisphenomenonistrue.Especiallywhendigitalcamerasusehighsensitivity,theseverenoisegeneratedbyCMOSorCCDisevenmoreunbearablefortraditionalphotographers.Thisisoneofthereasonswhymanyphotographersstillchoosefilmcamerastoshoottheirworks.

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