Laurence, Lionel · London, School of Optics · leaf 80
=fv A I=f2 and A C=r the radius of curvature.* 1\ Mi Un an ju2 Then Therefore 4j+-> M--7J or Vl+V±Jh_ fl2 - fl± The Focal Lengths and Powers of a Curved Surface.—The refractive power\/F of a curved surface depends on its curvature and the refractive index ofthe medium, so that an increase in… … Fig. 72. In Fig. 72 P is the principal or refracting plane where all refractiontakes place. C is the optical centre (or nodal point) because all rays passingthrough it are unrefracted. If light is parallel to the principal axis in thedense medium, on emergence into the rare medium it is refracted…
Optics
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