I need someone to tell me if I've done this right...

Trying to calculate prism in diopters given an index of refraction and the angle of a flat prism.

Prism angle = 4.1 deg
I = 1.52

If light is incident perpendicular to the front surface of the prism, the incident angle on the back side will be equal to the prism angle or 4.1 deg.

First determine the exit angle (theta) using Snell's law:

1.52 = sin(4.1)/sin(theta)

sin(theta) = sin(4.1)/1.52

theta = arcsin(0.047)

theta = 2.7 deg

Second using the trig formula for tan to determine the deviation at 100cm:

tan(2.7) = x/100cm

x = tan(2.7)(100cm)

x = 4.7cm or 4.7 prism diopters


thanks

Keith