Re: [ATM] Movement of the Secondary mirror in a Newtonian system

["Mel Bartels" <mbartels@bbastrodesigns.com>]

>              What if the secondary mirror was off axis from 45 degree to 
> say 40 degrees. Would this
>        not aim the focuser back towards the primary mirror (or to the 
> ground as in most scopes?)
>            What if you went to 35 degrees? I understand that the secondary 
> would have to have it's
>          long axis measure adjusted , but does this work , optically?
>                          Rethinking something that has already been done ,


This is the basis for folded reflectors - see Dan Gray's 28 inch and a 24 
inch by ??? before that.  I have a little program that will calculate the 
reduction in ladder height - it can amount to 1/3 of the scope height.

See http://www.bbastrodesigns.com/dnld/foldref.zip

Mel Bartels 

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