Analyze the surface of the mirror

Make a table of your measurements. Subtract z$_0$ from each measured z$_n$. Plot a graph of these correct $z$'s versus $h$. Overlay on this graph the values calculated for a perfect parabola from equation 7.1.

Verify the behavior you observed with the ray tracing program BEAM3. The files PARA.RAY and PARA.OPT will create a ray tracing for a parabola with a light source at its center of curvature, and for an image $2^\circ$ off-axis. The files FOUC.RAY and FOUC.OPT will repeat this tracing, but with only two rays. You can change the characteristics of those rays to test different zones. By using the AUTO feature, BEAM3 can be made to find the position of best focus for any zone. Does BEAM3 give the same answers that Equation 7.1 does?

How does the surface of this mirror differ from a parabola? In your answer to this question, discuss the accuracy to which you think the nature of the surface can be determined by this method.