Plectel 



Fiol Sh*pe of lenses -in section 



imTffiiiiiiiii.imTfflffl 



PI&Ao-convex. Double-convex. PUno-concd.veDouble-concexve. 



Meniscus. 



Fio2. Angles of incidence 



refraction. 



Coddir\eior\. 

 Flo3 v IS uaJ Anqle. 



Fic4.5pKencAl Aberration 



A B 5i/rf(\ce of dense mediun\ 



CD. Perpendicular EF Rejected i^y c 

 EG. Reflected KAy. abSinepf atn^Uif R 



irvcidence.a'b'Sine of Auyle oj refrvc1ion 



Fio6.Effectscf 



JJ niiiilmiirmJTT, 



B 



V R 



Fi&7 Immersiorv Objective. 



