Astronomy
My 10 inch Mirror with a 1/48 P-V Wavefront Error @ 550nm
In 1958 at Delbrook Sr. High School in North Vancouver BC, I was a member of the Physics Club. Having after school priviledges to use the physics lab, I spent many many hours grinding a couple of pieces of optically pure pyrex glass together to produce a perfectly spherical 10" reflector with a 108" radius of curvature. In following the instructions for a 6" mirror I reconfigured the mirror to a 10" design of my own.
This meant increasing the number of facets on the mirror's surface to compensate for the mirror's larger area, making it necessary to increase the number of strokes around the grinding barrel to 16 strokes per revolution from 8 strokes per revolution. It also meant selecting a different Focal Length for the mirror, to take advantage of the extra light. The new Focal Length meant a new Radius of curvature (108"), which meant more frequent testing in the grinding and polishing stages because I couldnt trust the 6" data on how many "wets" to expect before any particular stage of grinding is complete.