what is normal shift and apparent shift
1.Apparent shift:
The Apparent shift of the ray is the perpendicular distance between the incident and the emergent ray with reference to refraction of light through a glass slab.
2.Normal Shift (NS):
During refraction, the apparent shift in the position of the object along the normal is called normal
shift.
Consider denser medium ABCD of refractive index n1 and depth �t� surrounded by another medium of refractive index n2; assuming that (1) is denser and medium (2) is rarer like air.
NS= t [ 1 - n2/n1 ]
Apparent shift = Object distance from refracting surface � image distance from refracting surface.
?y (apparent shift) t = 1 - ?-1 where t is the object distance and ? = ?1/ ?2
� If there are a number of slabs with different refractive indices placed between the observer and the object.
Total apparent shift = ??yi