Re: ATM cassegrain

["James W. Burrows" <burrjaw@halcyon.com>]

At 22:43 97-09-28 -0400, Bill Hartung wrote:
>
>Is there any way to easily determine what type of cassegrain my ota is? The
>primary is a 1960's vintage coulter optical f/5 6", with matching secondary. 
>My research did not help to pin down the actual type.

It's probably a classical cass, parabolic primary, hyperbolic secondary.
Two possible tests:  1) Foucault on primary or 2) put a flat diagonal in
front of the secondary, see if it works as a Newtonian.


        -- Jim Burrows          phone 206-244-2933, fax -0294
        -- Email                burrjaw@halcyon.com
        -- Seattle              N47.4722, W122.3661 (WGS84)