8" Mirror Parabolizing: Oh No Not Again
I’m parabolizing my telescope mirror - I’ve ground it to a sphere shape, and now I’m grinding a tiny bit more to change its shape precisely into a parabola.
I’ve done 3 grinding sessions for a total of 34 minutes of grinding. Here’s a Ronchi picture of my current progress. Mel’s online Ronchi calculator has overlaid some semi-transparent white lines which show the ideal Ronchi grid of a somewhat parabolized mirror. Looks like the center is fine, but the edge is focusing light too close - similar to what happened in parabolizing attempt #1. I’ll need to think to figure out how to solve this.