Re: ATM Sept issue / Pantratz

[Michael Peck <mpeck1@ix.netcom.com>]

astrojoe@erols.com wrote:

>it was novel at the time; but given today's larger DOBs, 40" and up, it
>makes a lot of sense. I think we are going to see many more Mersienes
>DOBs in the near future. Sure beats climbing the 8-10 foot ladder. The
>

Why do you think that? In its classical form the Mersenne is just a
cassegrain (or gregory) telescope that happens to be afocal, which is done
using a pair of confocal paraboloidal mirrors. Even advanced ATMs by and
large fear tackling convex aspheric elements, and unless that changes
you're not likely to see a lot of Mersennes at your neighborhood star party
in the foreseeable future.

Some proposals for next generation extremely large telescopes use an afocal
mirror pair with a spherical primary as a feeder for a second image forming
system. Maybe a design along those lines with (perhaps) a refractor at the
back end would be of interest in a large amateur telescope. Might be worth
a look...

Mike Peck

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Michael Peck
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