[ATM] long focal length scope design \ Re: Cutting glass into large circles
David Weinshenker
daze39 at earthlink.net
Sun Dec 30 04:49:23 JST 2007
Bob May wrote:
> There's a picture of me on the RTMC website for the Merit Awards
> of 1998 adjusting the telescope for first light of the scope.
That would be this image?
http://www.rtmcastronomyexpo.org/archives/photos/98RTMC01.jpg
> The aperture on my scope is 4.25"
> and the focal length is approximately 200" so as a a result, I can
> put the lens of that scope on one edge of the Hale scope and
> focus at the other side of the telescope!
I remember thinking the same thing about the Swayze 40" f/5
reflector: http://www.europa.com/~swayze/photo/40inch.jpg -
at least your refractor didn't require the user to observe
from the top of a 17 foot ladder!
I really think a reflector on that scale might best be built
in the "Nasmyth" or "coude Cassegrain" layout, with a convex
secondary mirror, and a final flat diagonal mirror just in
front of the primary that would reflect the light toward an
eyepiece located on the side of the mirror box (about at the
axis of rotation of the altitude bearings) - it's not really
big enough for what they did with the Hale scope itself, which
included a seat for an observer to ride inside the scope, up
at the prime focus!
-dave w
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