Theforerunnertothecamerawasthecameraobscura.Thecameraobscuraisaninstrumentconsistingofadarkenedchamberorbox,intowhichlightisadmittedthroughaconvexlens,forminganimageofexternalobjectsonasurfaceofpaperorglass,etc.,placedatthefocusofthelens.ThecameraobscurawasdescribedbytheArabicscientistIbnal-Haytham(Alhazen)inhisBookofOptics(1015–1021).Alhazen'sworkappearedinLatintranslationasDeAspectibus("Concerningvision")inabout1200,andthebookinfluencedRogerBacon'sreflectionsonproducingimagesusingpinholes.Bacon'snotesanddrawings,publishedasPerspectivain1267,arepartlycloudedwiththeologicalmaterialdescribinghowtheDevilcaninsinuatehimselfthroughthesmallestofspacesbymagic,anditisnotclearwhetherornotheproducedsuchadevice.On24January1544mathematicianandinstrumentmakerReinersGemmaFrisiusofLeuvenUniversityusedonetowatchasolareclipse,publishingadiagramofhismethodinDeRadioAstronimicaetGeometricointhefollowingyear.In1558GiovanniBatistadellaPortawasthefirsttorecommendthemethodasanaidtodrawing.TheactualnameofcameraobscurawasfirstappliedtothetechniquebymathematicianandastronomerJohannesKeplerinhisAdVitellionemparalipomenaof1604;hewouldlaterimprovetheapparatusbyaddingalensandmakingittransportable,intheformofatent.IrishscientistRobertBoyleandhisassistantRobertHookelaterdevelopedaportablecameraobscurainthe1660s. 　　ThefirstcamerathatwassmallandportableenoughtobepracticalforphotographywasbuiltbyJohannZahnin1685,thoughitwouldbealmost150yearsbeforetechnologycaughtuptothepointwherethiswaspractical.EarlyphotographiccameraswereessentiallysimilartoZahn'smodel,thoughusuallywiththeadditionofslidingboxesforfocusing.Beforeeachexposure,asensitizedplatewouldbeinsertedinfrontoftheviewingscreentorecordtheimage.JacquesDaguerre'spopulardaguerreotypeprocessutilizedcopperplates,whilethecalotypeprocessinventedbyWilliamFoxTalbotrecordedimagesonpaper. 　　第二段写camera何时怎样发明的 　　整个你可以当camera的简史