HongKongPolytechnicUniversityLightControithroughOpticalSystemOur major concerns:field ofview and image brightnessWe will learn: aperture, stop,aperture stop, field stop, pupil and window.The element in an optical system that determines the maximum cone oflight passing through the system is called the aperture stop (AS).The limiting cone angle aα, is easy to obtain but α, is not.LIL2(a)L1L2(b)Optics1----byDr.H.Huang,DepartmentofAppliedPhysics
Hong Kong Polytechnic University Optics 1-by Dr.H.Huang, Department of Applied Physics 1 Light Control through Optical System Our major concerns: field of view and image brightness We will learn: aperture, stop, aperture stop, field stop, pupil and window. The element in an optical system that determines the maximum cone of light passing through the system is called the aperture stop (AS). The limiting cone angle 1 is easy to obtain but 2 is not
HongKongPolytechnicUniversityLightControithrouahOpticalSvstemFrontLensstopMR0ChiefrayChiefrayFMRE,PASE.P(realimage)Afront stop serves as an aperture stopEntrance pupil (E,P): the image of AS seen through the optical elements infront of it.Exit pupil (E,P): the image of AS formed by all imaging elements following it.E,P is conjugate with E,P.2Optics1----byDr.H.Huang,DepartmentofAppliedPhysics
Hong Kong Polytechnic University Optics 1-by Dr.H.Huang, Department of Applied Physics 2 Light Control through Optical System A front stop serves as an aperture stop. Entrance pupil (EnP): the image of AS seen through the optical elements in front of it. Exit pupil (ExP): the image of AS formed by all imaging elements following it. EnP is conjugate with ExP
HongKongPolytechnicUniversityLightControithroughOpticalSystemRearLensstopArearstopbehindthelensMROserves asthe aperture stop (AS)Chiefraand the exit pupil (E,P)ChiefrayASE,PE.PFrontLens(virtual image)stopMRa1Afront stopserves astheMEaperturestop (AS)andtheChief rayentrancepupil (E,P).ASE,PEP(virtualimage)3Optics1----byDr.H.Huang,DepartmentofAppliedPhysics
Hong Kong Polytechnic University Optics 1-by Dr.H.Huang, Department of Applied Physics 3 Light Control through Optical System A rear stop behind the lens serves as the aperture stop (AS) and the exit pupil (ExP). A front stop serves as the aperture stop (AS) and the entrance pupil (EnP)
HongKongPolytechnicUniversityLightControithroughOpticalSystemChief ray: a ray from object that passes through the axial point in E,P. Theray must also passes throuahthe axial point of both the AS and E.P.S;S2L2L2MRChiefrayChiefray8MRASE.PE,PEntrance and exit pupils are relatedto AS andgovern the brightness oftheimage.Optics1----byDr.H.Huang,DepartmentofAppliedPhysics
Hong Kong Polytechnic University Optics 1-by Dr.H.Huang, Department of Applied Physics 4 Light Control through Optical System Chief ray: a ray from object that passes through the axial point in EnP. The ray must also passes through the axial point of both the AS and ExP. Entrance and exit pupils are related to AS and govern the brightness of the image
HongKongPolytechnicUniversityLightControithroughOpticalSystemThe field of view describes the range of the objectLensthatcanbeviewed.StopSThe partial shielding of the outer portion of the1Oimage by stop S for off-axis object points is calledvignetting. Excessive vignetting may make theObjectimage of a point object appear astigmatic.ImageplaneplaneThe field of view (object plane) is often defined asLenthe circle (OU) that consisting of all object pointsStophaving at least half the maximum irradiance found atraythecenteroftheimage.UTOField stop (FS) limits the size or angular width of theTUobjectthatcanbeimaged.VImageplaneObjectEntrance window (E,W): the image of FS formed byplaneall opticalelementsprecedingit.E,WASL2FS4L1E,WE,PE,PExit window (ExW): the image of FSformedbyall optical elementsfollowingit5Optics1----byDr.H.Huang,Department ofAppliedPhysics
Hong Kong Polytechnic University Optics 1-by Dr.H.Huang, Department of Applied Physics 5 Light Control through Optical System The field of view describes the range of the object that can be viewed. The partial shielding of the outer portion of the image by stop S for off-axis object points is called vignetting. Excessive vignetting may make the image of a point object appear astigmatic. The field of view (object plane) is often defined as the circle (OU) that consisting of all object points having at least half the maximum irradiance found at the center of the image. Field stop (FS) limits the size or angular width of the object that can be imaged. Entrance window (EnW): the image of FS formed by all optical elements preceding it. Exit window (ExW): the image of FS formed by all optical elements following it