I'm hoping for the day when physicists find (if it indeed exists) the relationship between gravity and electromagnetic forces, and are able to make an artificial gravitational field; just imagine a scope with an onobstructed large ring at the objective end able to generate a gravitational field powerful enough to bend the light passing through it much like a refractor without the glass; same thing at the eyepiece end, variable power without anything solid between your eye and the deep sky... how cool would that be? -Rich --- Chuck Hards <chuckhards@yahoo.com> wrote:
--- David Dunn <david.dunn@albertsons.com> wrote:
Good page. It makes me wish that I could start now. Luckily I wont have to hog mine out as deep since I want to go with an f/10. One question I have is why do you use a flat for the optical secondary instead of a parabolic 8" mirror?
If the secondary is anything but flat, it will alter the primary f/#. Also, a flat is infinitely easier to figure than just about any convex surface. A concave secondary means a Gregorian configuration, which tends to be much longer than a Cass, and even most Newts.
If you really want to go unobstructed, check out the Sasian design- of course it means you must figure a toroidal secondary (royal pain in the butt). All in all, a "folded" Newt is a marvel of optical simplicity.
C.
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