Re: ATM 16" F/33 valid design?

[Andy Saulietis <iss@pvtnetworks.net>]

Dominic writes:


>thought... I have an 18" mirror, soon to become
>a slow Newtonian. Maybe its actually justified to
>core this beast and give it a Cass secondary, with
>a system EFL around F/30. I guess I could still use it
>as a Newt. On the other hand, I guess Schaer, being
>Swiss, might have had access to exceptional real
>estate for that scope, like the Swiss Alps, not to
>be compared to the Swedish Alps.

A 5x Tele-vue barlow would be a *lot* easier & have a
shorter air path thru the OTA as well...I considered
making a Herschelian (concave secondary) for my 32"
but will go with barlow instead.


Andy Saulietis
ISS Enterprises
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Mayhill NM 88339
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e-mail: iss@pvtnetworks.net