L4 Reflectn Refractn at Spherical Surfaces and Curved Mirrors Flashcards
explain radius for spherical surface
- follows sign convention rule
- radius is positive when CENTRE of curvature is on RIGHT hand side of REFERENCE point
explain vergence in spherical surfaces
change in vergence is directly proportionate to radius of surface
radius-power relationship (calculation)
F = n’ (right) - n (left) / r (in m)
explain object space in spherical surfaces
- left side of interface
- object within =real, image within =virtual
- object emits divergent rays hence negative vergence
- in front ref point hence negative object distance
explain image space in spherical surfaces
- right side of interface
- image within=real, object within=virtual
- image formed by convergent rays hence pos vergence
- behind ref point hence pos image distance
explain incident/object vergence (L)
L = n (left) / l (object distance)
explain emergent/image vergence (L’)
L’ = n’ (right) / l’ (image distance)
object-image relationship (calculation)
aka gaussian imaging eqn
L’ = L + F
define optical axis
line passing thru centre of curvature. the whole optical system is CENTRED and SYMMETRICAL about this axis
define vertex
the point where the optical axis passes normally through the refracting surface
define axial points
points on the optical axis
define chief ray
a ray that passes through the refracting surface without being deviated
explain paraxial and non-paraxial
paraxial rays will focus on a single point, non-paraxial rays focus on various locations
explain primary focal point for spherical surfaces
when object at primary focal point, image is at infinity
explain secondary focal point for spherical surfaces
when an object is at infinity, image will be formed at the secondary focal point
