ATM Re: 18-inch Dob vs 10-inch SCT

[Atmj1@aol.com]

The Lowly SCT

I have watched with interest as the SCT has taken it in the shorts when
compared to the Newtonian. That, aperture per aperture, is as it should be.
However, isn't comparing an 18-inch Dob to a 10-inch SCT a bit much?

A number of List subscribers are quick to point out that SCTs are being mass
produced and tha that is at least part of the reason for the bad image. Still
we should keep in mind that many of the SCTs produced today are not even
coming close to providing the performance that an SCT of a given aperture is
CAPABLE of providing when enough time is spent on figuring.

I have talked to a number of you who have looked through some of the early
Celestrons and who still remember the fantastic performance. Yes, there are
some first order considerations that make the Dob a superior choice for some
people. However, just because the major manufacturers can't spend a week's
budget on one instrument, it doesn't mean that the concept is faulty. 

I have always told the Newbie that an SCT is not a "first" ATM project but
rather a "last" project - knowing of good opticians who grew old trying to get
it right. Still, that is not to say that we should stop trying. I have been
thinking about new techniques for making and testing Schmidts myself and would
encourage others - who have already made a few other instruments to do the
same. 

Just because it is the hardest corrector to make today, it doesn't mean that
there is not some young guy or gal out there smarter and more bull headed than
the rest of us who may have a solution up their sleeves or between their ears.

Just a thought.

Regards,
Bill Cook