Consider a convex lens with the first surface having a radius of curvature of 31.123mm, a lens thickness of 5.8mm, and the second surface of the lens is flat. The lens is made from a glass whose diameter is 30mm.
Assume that an object is held 300mm to the left of the lens that glows at two wavelengths 486.1 nm blue and 656.3nm red. The refractive index of the lens at these two wavelengths is 1.522376 for the blue and 1.514322 for the red. Because the refractive index is not the same for both wavelengths, there will be two images. Find the image distances from the rear surface of the lens for each of these two wavelengths, as well as the focal lengths.
Assume the object is a star and that you focus on the red image. What is the diameter of the blue image as predicted by paraxial ray tracing.