what are the appropriate lenzes for making a powerful telescope by myself?

Answer 1

Normally a home made telescope consists of a hand ground or purchased concave mirror, a short focal length eye piece lens, an elliptical first surface mirror and a cardboard tube to mount the optics. You can purchase a blank from Edmond scientific and grind and polish the objective mirror your self. Then send it off to be aluminized. The whole process usually takes 4 to 6 months. When you say powerful, it means larger diameter objective. Eight inch is normal, fourteen inch is super.