what is normal shift and 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
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