TechnologyofPhotographyClaudiaJacquesdeMoraesCardoso

Based on Alex Sirota http://iosart.com/photography-art-or-science

CameraObscura

Camera Obscura, Georg Friedrich Brander (1713 - 1785), 1769

LightSensitiveMaterials•  Afterthecameraobscurahadbeeninventedandit’suse

widelypopularized,manydreamtofcapturingtheimagesobtainedbythecameraobscurapermanently.

•  Forhundredsofyearsbeforephotographywasinvented,peoplehadbeenawarethatsomecolorsarebleachedinthesun,buttheyhadmadelittledistinctionbetweenheat,airandlight.

•  In1727,JohannHeinrichSchulze(1687-1744),aGermanscientistfoundthatsilversaltsdarkenedwhenexposedtosunlightandpublishedresultsthatdistinguishedbetweentheactionoflightandheatuponsilversalts.

•  Evenafterthisdiscovery,amethodwasneededtohaltthechemicalreactionsotheimagewouldn’tdarkencompletely.

A Simplified Schematic Representation of the Silver Halide Process

FirstPermanentPicture

JosephNicephoreNiepce(1765-1833),aFrench

inventor,wasexperimentingwithcameraobscuraand

silverchloride.

•  In1826,heturnedtobitumenofJudea,akindofasphaltthathardenedwhenexposedtolight.

•  Niepcedissolvedthebitumeninlavenderoilandcoatedasheetofpewterwiththemixture.

•  Heplacedthesheetinthecameraandexposeditforeighthoursaimedthroughanopenwindowathiscourtyard.

•  Thelightformingtheimageontheplatehardenedthebitumeninbrightareasandleftitsoftandsolubleinthedarkareas.

•  Niepcethenwashedtheplatewithlavenderoil,whichremovedthestill-softbitumenthathadn’tbeenstruckbylight,leavingapermanentimage.

•  Niepcenamedtheprocessheliography-Greek,helios-“sun”,graphos-“drawing”.

View from the Window at Le Gras, Joseph Nicephore Niepce, 1826

Daguerreotypes

NewsofNiepce’sworkhadreachedanotherFrenchman,

LouisJacquesMandeDaguerre(1787-1851)whohadbeenexperimentingtocapturecameraobscuraimages.

•  In1829NiepceandDaguerrebecamepartners,apartnershipwhichlasteduntilNiepce’sdeathin1833.

•  Daguerreperfectedtheprocess,reducingtheexposuretimefromeighthourstohalfanhour.Hefoundthatanimagecouldbemadepermanentbyimmersingitinsalt.

•  In1839heannouncedthenewprocesswhichhenamed“daguerreotype”beforetheFrenchAcademy.

•  AFrenchnewspaperpraisedtheprocess:“Whatfinenessinthestrokes!Whatknowledgeofchiaroscuro!Whatdelicacy!Whatexquisitefinish!…Howadmirablyaretheforeshorteningsgiven:thisisNatureitself!”

•  Almostimmediatelyaftertheannouncement,hundredsofdaguerreotypestudioswereopenedtoprovide“SunDrawnMiniatures”tothepublic.

•  By1853anestimatedthreemilliondaguerreotypesperyearwereproducedintheUnitedStatesalone.

StillLifeinStudio,LouisJacquesMandeDaguerre,1837Theearliestknowndaguerreotype

DaguerreotypeofCoupleHoldingDaguerreotype,UnknownArtist,1850

EmilyDickinsonat17,UnknownArtist,1847

FollowingAchievements•  Daguerreotypeshadonemajordrawback,therewasnowayof

producingcopiesoftheoriginalplate.•  InJune1940,anEnglishamateurscientistHenryFoxTalbot

(1800-1877)announcedatechniquewhichbecamethebasisofmodernphotography.Hecalledit"calotype"(Greekfor"beautifulpicture").

•  ThegreatadvantageofTalbot'smethodwasthattheprocessinvolvedbothanegativeandapositive.Thenegativeimage,thecalotype,wasrepeatableindefinitelyinapositiveprint,finallyallowingmultipleprints.

•  By1880,aconvenient“dryplate”processwasdeveloped,allowingveryfastdevelopmentandopeningthefieldtothegeneralpublic.

TheOpenDoor,WilliamHenryFoxTalbot,1843

XieKitchinwithUmbrella,LewisCarroll,1875

RollFilm

MuchofthecreditforpopularizingphotographygoestoGeorgeEastman(1854-1932).HebeganasabankclerkinRochester,NY,andbuilthisEastmanKodakCompanyintoagreatenterpriseitistoday.

•  In1884Eastmaninventedtheequipmenttomassproduceroll

film.“Eastnman’sAmericanFilm”wasarollofpapercoatedwiththingelatinemulsion.

•  Rollfilmmadepossibleanewkindofcamera-inexpensive,lightandsimple-thatmadeeveryoneapotentialphotographer.

•  Intheearlyyearsofthecompany,filmbasewasmanufacturedandcoatedonlongglasstables.

RoyalGoldKodakfilm,1994

KodakCamera•  Kodakcamerawasintroducedin1888.Theirsloganwas

“Youpushthebutton,wedotherest”.•  TheKodakcamerabecameaninternationalsensation

almostovernight.•  Anewphotographicera,ofsimplelightcamerasandeasy

tohandlerollfilmhadbegun.

ThefirstKodakcamera,1888

Kodakcameraadvertisement,1890

GeorgeEastmanwithaKodakcamera,Fredrick

Church,1890

Color-FirstSteps

Maxwelldevisedawaytorecreatethecolorsofatartanribbon.Hehadthreenegativesoftheribbonmade,eachthroughadifferentcolorfilter-red,greenandblue.

Oneofthefirstsuccessesincolorphotographywasdemonstratedin1861bytheScottishphysicistJamesClerkMaxwell(1831-1879).

• Positiveblackandwhitetransparenciesweremadeofthethreenegatives.Whileprojectedsuperimposedthoughthreecolorfilterslikethoseonthecamera,thethreepositivesproducedanimageoftheribboninit’soriginalcolors.

• Thistechniqueiscalled“additivecolormixing”.Colorsareproducedbyaddingtogethervaryingamountsofred,greenandblue.

Maxwell’startanribbon

SubtractiveColorMixing

SubtractiveColorMixing

•  In1869,LouisDucosduHauron(1837-1920)andCharlesCros(1842-1888),twoFrenchmanworkingindependentlyannouncedtheirresearchonsubtractivecolormixing.

•  Insubtractivecolormixing,whichisthebasisformoderncolorphotography,colorsarecreatedbycombiningcyan,magentaandyellowdyes(thecomplementsofred,greenandblue).Thedyesaresubtractcolorsfrom“white”lightthatcontainsallcolors.

LouisDucosduHauronLeavesandFlowerPetals,1869

CommercialColorPhotographyThefirstcommerciallysuccessfulcolorprocesswasdevelopedbyAntoineandLouisLumiere,twoFrenchbrothers,in1907.Itwasanadditiveprocesscalled“Autochrome”.

Jean-BaptisteTournassoud(1866-1951),Autochrome,Early20thcentury.

Autochrome

•  Aglassplatewascoveredwithtinygrainsofpotatostarchdyedred-orange,greenandvioletinalayeronlyonestarchgrainthick.

•  Thenalightsensitiveemulsionwasadded.Lightstrucktheemulsionafterpassingthroughthecoloredgrains.Theemulsionbehindeachgrainwasexposedbylightfromthescenethatwasthesamecolorasthatgrain.

•  Theresultwasafullcolortransparency.

Jean-BaptisteTournassoud,Autochrome,Early20thcentury.

AutochromelandscapeofMadeirabyMissSarahAngelinaAcland,1908-15

Kodachrome•  Asubtractivecolorprocesscalled

kodachromemadecolorphotographypractical.

•  ItwasperfectedbyLeopoldMannes(1899-1964)andLeopoldGodowsky(1900-1983),twomusiciansandamateurphotographicresearchers.

•  TheircollaborationwithEastmanKodakscientistsledtotheintroductionofKodachromein1935.Kodachromewasasinglesheetoffilmcoatedwiththreelayersofemulsion,eachsensitivetooneprimarycolor(red,greenandblue).Asingleexposureproducedacolorimage.

1935

2000

LuisMardenCareerCollage,SarahLeen

LuisMarden,agreatphotographerworkingfortheNationalGeographicSocietywasoneofthefirstpioneersoftherevolutionarynewfilm.

Party-maskwithShells,PaulOuterbridge,1936

DigitalPhotography

•  Inthemid1970s,Kodakandothercompaniesbeganinvestigatingfilmlesstechnologiesthatcouldcaptureimageswithsolidstatecircuitry

•  In1986,Kodaksucceededincreatingasensorthatcouldrecord1.4millionpictureelements,ormegapixels.

•  Inthe1990sthefirstdigitalcamerasappearedforcommercialuse.

KODAKPROFESSIONALDCS760DigitalCamera,6millionpixels,2001

•  Thebigdifferencebetweentraditionalfilmcamerasanddigitalcamerasishowtheycapturetheimage.

•  Insteadoffilm,digitalcamerasuseasolid-statedevicecalledanimagesensor,usuallyacharge-coupledevice(CCD).

•  Onthesurfaceofeachofthesefingernail-sizedsiliconchipsisagridcontaininghundredsofthousandsormillionsofphotosensitivediodescalledphotosites,photoelements,orpixels.Eachphotositecapturesasinglepixelinthephoto-graphtobe.

Animagesensorsitsagainstabackgroundenlargementofitssquarepixels,eachcapableof

capturingonepixelinthefinalimage