Just thinking out loud here - what would be the main obstacles to a H-alpha newtonian with an uncoated mirror focusing onto an assembly consisting of a collimating lens-ERF-etalon-focusing lens-secondary mirror (all of these held by a beefy spider assembly), and a blocking filter or quark (if we lose the etalon in the main tube) in the focuser? Would that not work in principle? 8-12 inches of aperture, maybe. Or am I missing something?
One problem would be 'seeing', my understanding is that for the sun, seeing would be very poor at more than a few inches of aperture.
I have wondered about something like the mylar films, to reduce the suns energy down to a few percent, then through the (interchangeable) narrow band filters required to view suns atmosphere and surface features.
True but let's assume one has access to a site with great seeing.
You'd have to lug way less than this thing, get almost the same resolution (with a 12") all at 1/10 of the cost
