6.1NaturalofLight光的性质whatislight?Lighttravelinstraightlinesbutcanbeaffectedbythefollowingeffects.LighttravelinstraightlinesReflection反射Refraction:折射Diffraction:衍射whatisVisibleradiation可见光Whatiswhitelight?什么是白光？Whitelightcanbeseparatedintoitscomponentwavelengthsusingaglassprism棱镜,whatisNon-visibleradiation不可见光Infra-redradiation红外线Ultra-violet紫外线thestructureoftheeyeConevision锥体细胞isadaptedtonormallevelsoflightandisusedtoforseeingdetailsanddistinguishcolourRodvision杆状细胞isadaptedtoverylowlevelsoflightandisverysensitivetolightbutcannotdistinguishcolourterminologyofvision视觉术语6.3howtomeasurelighting光的度量whichonecangivemorelight?whatisSolidangle立体角Acompletespherecontainsatotalof4steradianswhichonewouldyouchoose?Illuminance照度21Inversesquarelawofillumination照度的平方反比定律Workedexample6.2Cosinelawofillumination照度的余弦定律Workedexample6.3Diffusereflection漫反射Workedexample6.430thecandelapersquaremetreisthecorrectSIunitofluminance.Theapostilbisanalternativeunitofluminancewhichisconvenientforsomecalculations1apostilb=1/cd/m2Self-luminoussources自发光光源TheluminanceisgivenbyAgoodlightenvironmentrequiresasuitablelightdistributionwhatisGlare眩光howtomeasureLight?DoeslighthasDirectionalquality?光有方向吗？Wecandescribeitsdirectionalpropertyusingthefollowingparameters6.4Color色彩pleasereadthispartbyyourselfafterclass6PrinciplesofLightExerciseintheclass4Linkthefollowingtwocolumnsbylines1Solidangle2Luminousintensity3luminousflux4illuminance5luminance