Unformatted text preview: 6.2.3 Principal planes The nodal points N of a lens are de±ned by the ±gure on the right. If the lens is surrounded by the same medium on both sides, the nodal points are the same as the principal points H. The plane ⊥ the optical axis through the principal points is called the principal plane . If the lens is described by a matrix m ij than for the distances h 1 and h 2 to the boundary of the lens holds: h 1 = n m 11-1 m 12 , h 2 = n m 22-1 m 12 ± ± ± N 1 N 2 O 6.2.4 Magnifcation The linear magnifcation is de±ned by: N =-b v The angular magnifcation is de±ned by: N α =-α syst α none where α sys is the size of the retinal image with the optical system and α none the size of the retinal image without the system. Further holds: N · N α = 1 . For a telescope holds: N = f objective /f ocular . The F-number is de±ned by f/D objective ....
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- Spring '10
- Power, Optical axis, mirror Concave mirror, mirror Convex mirror