Re: [ATM] Blank question

["Bob May" <bobmay@nethere.com>]

Yeppie, one of the things that people often don't figure in when they want a
big scope is the minimum magnification that is required to get the full
aperture to the eye.
When you get to a meter diameter scope, the minimum magnification is 1000/7
is about 142 power!  That is getting into the planetary viewing
magnifications.
Along with the high power needed is that you need to use some really large
eyepieces just to get the full FOV that you could get as the focal length is
getting long.  A F3 mirror is 3 meters for the focal length which means
about 120" of focal length and that means that a 25mm EP is about the
longest EP that you would even consider as that will give 120 power, not
enough to fill the aperture!
When things get big, some of the assumptions that have normally been used
end up not being quite true.
Bob May
bobmay@nethere.com
http://nav.to/bobmay
http://bobmay.astronomy.net

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