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Recent Article In ATMJ

Val Germann
Central Missouri Astronomical Association

This article came about after Dr. Russell's image simulation
showed that a Newtonian of small obstruction, made with a 5.5-inch
spherical mirror of good quality, appeared slightly better than
a standard 4-inch doublet refractor, and not grossly inferior to
a 6-inch APO.  We stand by these results.

At AstroFest last year we showed a 6-inch Newtonian of very high
quality, with an E&W fused-quartz secondary of 1.25" minor axis.
We had quite a crowed around most of Saturday evening because
of our "mirror-in-a-day" demo and a couple of them were going
back and forth between our 6-incher and the nearby AstroPhysics
refractors, the factory ones set up by Roland and his compadres.
About 10 pm Tom Martinez of the Kansas City club came over to
me and asked me about the six-inch, saying it was in the same
basic class as the 7-inch StarFire sitting about 100 feet away.
I said, "Tom, I can't take credit for that Newtonian, the mirror
was made by Criterion about 25 years ago."

So, I think we have been justified in our basic conclusions about
the ultimate quality possible in Newtonians in the 6- to 12.5-inch
class, where we have been running simulations.  Mark's personal
12.5-inch mirror, which he made a couple of years ago, passes the
star test at f/4.0, no mean achievement, and the scope we made with
that mirror simply annihilates any refractor in the 6- to 7-inch
class.  More than one disinterested person has told us so.

The two 8-inch telescopes we had set up at Riverside and Astrofest
in 1995 were interferometrically tested by a third party and found
to be 3/8-wavefront and 1/5-wavefront as SYSTEMS.  The lesser of
these two was identified as absolutely average by our observers
while the better of the two was identified as far above average.

We owe apologies to our observers because we promised them a paper
in addition to our other inducements. . .a paper that we haven't
really written yet.  But we will.  This research proved to be so
expensive that I don't think we'll be going on to level two for
awhile yet.  It cost us several thousand dollars to find out what
we have found out so far.

Now, as to the ATMJ article and our process, the copy I have on
file reads "simplified star test" because we intend to have our
makers put a 25 percent occulting disk in the tube and use Suiter's
method to find out if 1/4-wave correction has been achieved, and
how to get closer to it, if it has NOT been achieved.  Our mirror-
in-a-day turned out pretty good, with no attempt at correction of
any kind.  We think that with a little care a quite good surface
can be made without ever resorting to the Foucault Test, at f/9.

I am currently putting the finishing touches on the instructions
we will be sending out to ATMJ readers who requested more info on
our methods.  If any list members would like one, send an SASE to:

Val Germann
110 Bourn Avenue
Columbia, Missouri  65203

I know I have disappointed in the past responding to these things
but I will do my best to get this material back to you in good time.

Thanks for everyone's patience and forebearance,

Val

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