Card Set Information

2011-11-14 22:48:55

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  1. Curvature of surface
    • the angle turned through per unit length of arc
    • R = 1/r in Dioptre (D)
  2. Refraction
    Light passes through an interface b/t 2 optical media
  3. Reflection
    Light bounces at interface
  4. Image
    New wavefront curvature (vergence in air) L' gives distance to image
  5. More curvature ->
    more vergence changing power
  6. Lens gauge/clock/measure
    measures surface power by measuring the sag of a lens of a specific refrative index
  7. Centered or symmetrcal elements
    elements positioned such that they have a common axis
  8. Surface power
    • Measure of the ability of the surface to change the vergence of light
    • Fs = (n'-n)/r = n'/f' = -n/f
    • in Dioptre
  9. Chief ray of extended object through a spherical surface
    ray passes through the center of curvature (it is undeviated because it is normal to the spherical surface)
  10. Lens
    has two refracting surfaces (both surfaces spherical or one surface may be plano (plane, no curvature, zero power))
  11. Center thickness
    Thickness at the vertex of the lens
  12. Thin lens
    negligible centre thickness, change in vergence as light passes through the lens is insignificant
  13. Biconvex/concave
    both surfaces are have the same sign but different powers
  14. Equiconvex/concave
    both surfaces have the same power
  15. Meniscus
    center of curvature is on the same side of lens for both surfaces
  16. planoconvex/concave
    zero power on one side, all power on other side
  17. Lens form (bending)
    any power of lens can be obtained by a combination of surface powers
  18. Principal foci
    • Light from infinity (parallel) passes lens and focuses at the SECOND prinicipal focus
    • Light emerging from FIRST principal focus emerges from the lens parallel
  19. Symmetric planes
    • closest possible distance b/t a real object and its real image in a plus lens
    • OR
    • closest possible distance b/t a virtual object and its virtual image in a minus lens
  20. Principal plane
    location of object and image when m=+1