Immersion Oil and Refractive Index

Numerical Aperture (NA) = n sin(θ)

NA = 1.51 sin(65°)

1.38 = 1.51 sin(65°)

θ = Angular Aperture = 65°

Objective Front Lens

Object Space

n = 1.51

Cover Glass

Specimen

Microscope Slide

Refractive Index = n

Low

High