Re: ATM 3" 75mm or 4" 100mm eyepieces

[kevin@aquilagroup.com (Kevin Ferguson)]

At 09:54 PM 8/19/96 -0400, K1JJ@aol.com wrote:

>My GOAL here is a wider field of view at reduced power for comets, enjoyment,
>etc. If I were to use a 3" diameter 75mm  with the 22" F8.5 this yields 61X
>with an exit pupil of 8.8.

Before spending big bucks on glass for an eyepiece, I hope you have
calculated how much FOV your tube will allow. 

I figured my tube based on a 1.25" maximum field of view.  It wants to be
tight for glare reduction.  I am assuming others do something similar, so
your secondary cage or whatever may be the limiting factor, rather than
eyepieces.  With such a slow scope, the falloff from nearly any source of
vignetting will be pretty abrupt.

-KF-