Show that the deviation angle for a ray striking a thin converging lens at a distance d from the principal axis is given by

Show that the deviation angle δ for a ray striking a thin converging lens at a distance d from the principal axis is given by δ = d/f. Therefore, a ray is bent through an angle δ that is proportional to d and does not depend on the angle of the incident ray (as long as it is paraxial).

-E 8 =B+Y B C Y D -P- (Angles are greatly exaggerated for ease in labeling.) B d