I think I was told once its Gregorian - note the long tube for the 4' ap at f/6.
Only the Gregorians had such low focal lengths - ???
jerry
David Knisely wrote:
Thomas M wrote:
I thought the SCT principle was much younger than that...its an F6 SCT in
the article
The reflector in the article is not an SCT. It is a simple Cassegrain,
possibly Classical or Gregorian, as the Gregorians were often resorted to
during the era of the "brass" telescope (the tube length argues for a
Gregorian). The SCT is a different and much more recent design (circa 1962)
using spherical optics and a large corrector plate. Clear skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/
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