🔭 Reflector Telescope Mirror: Conic Constant, Spherical Aberration, Coma and Spot Diagram (2D)

Section of a concave telescope mirror traced ray by ray, with a spot diagram at the focus. Set the mirror diameter, the focal ratio, the conic constant from a sphere to a paraboloid, the angle of the star off the axis, the wavelength and a focus shift, and see the rays, the spot size, the wavefront error and the Strehl ratio. A perfect paraboloid, the sphere path error, the spherical aberration and the coma flare are checked against formulas with four in-page numerical checks.