You have a wonderful sized solar scope. Before you do indeed start making a scope with it, I would recommend that you do a Foucault test and use a finder scope or so behind the knife edge to get a better view of the mirror. You focus the scope on the mirror and place the knife edge so that it covers half of the objective lens. You don`t need a large scope for diameter as the only light of interest is that from the small area of the knife edge and the rest is just wasted area. The mirror is going to be about 160" away so you`re going to want some optical assistance. The mirror should be a perfect sphere to be good.
Leonard Higgens did a spectrohelioscope and has pictures and some text at http://sunmil1.uml.edu/eyes/lhiggins/neweb3.html and I`ve seen the instrument and it`s rather interesting. The image of the sun will be about three quarters of an inch in diameter so you will have a nice view of the sun.

• RE: RE: My 6 - bobmay - March 22, 2000 - 19:41 UTC