Re: ATM 16" F/33 valid design?

[Andy Saulietis <iss@pvtnetworks.net>]

At 08:12 PM 1/15/02 +0100, you wrote:
>
>
>Attention focal length extremists...
>
>This matter of sanity in focal length choice comes up
>periodically. I recall The Simak paper in Astronomy
>magazine in April 1984 mentioning that focal length
>of 120" was chosen for one of the major observatories
>because it was effectively the upper limit for the
>conditions  at this site, located on prime observing
>real estate presumably. I leave it to the readers to
>decide whether they agree with this very general statement.
>On a lot of the nights I have observed, even this seemed
>useless to me, so I never gave much serious thought to very
>long scopes and could not think of any major discoveries
>made with such Earthbound scopes that we ATM mortals
>would have access to (i.e., ATM scopes).
>
>The February issue of S&T is out and there is an
>articule there about Emile Schaer's telescope and
>the "F" ring of Saturn. I have not seen this ring
>through any scope, but it seems Schaer did, with
>a 16" F/33 Cass (i.e., fl = 528"). Interesting
>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.
>
>:)
>
>
>Cheers,
>
>
>
>Dominic
>
>North 59 37' 30"
>East  17 48' 10"
>
>
>
Andy Saulietis
ISS Enterprises
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Mayhill NM 88339
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