Re[3]: ATM Foucault telescope lense?

[Dwight Elvey <elvey@hal.com>]

UC007@aol.com wrote:
> Dwight,
> A cheap air rifle telescopic sight with the cross hairs removed does great.
> Bill

Hi
 One big advantage of using this method would be that
it keeps one form needing to be real close to the knife
edge. Both a safety hazard and sometimes difficult
position. A cheap zoom scope might work well for
different sized mirrors ( it is the F ratio that
counts ).
 I don't have a telescope on mine but have thought
about it. If I do, the rifle scope might be the
ticket.
Dwight