4 ms·
f/2.89 is a very fast scope. The sagitta or "depth of the parabola" of his mirror is almost 1cm.
by s800 6y ago
f/2.89 is a very fast scope. The sagitta or "depth of the parabola" of his mirror is almost 1cm.
- TwoBit 6y agoSeems like it would take a long time to grind. I can imagine targeting something shallower but not getting it right and keep fixing it and end up with a deeper lens.