Re: ATM 3 or 4 vane Spider

["William A. Morgan" <sass5@erols.com>]

Art,

I have a 3 vane on my 10"f6 made by ProtoStar and works great! No problem with
spikes and I get perfect pin point stars.

Good luck,

Bill

Art Russell wrote:

> I'm contemplating ordering either a 3 or 4 vane spider for a 6 inch, F4
> Newtonian for which I'm currently polishing the mirror.
>
> Any comments about the current thinking about the best way to minimize
> difraction spikes? 4 vanes seem to be self reinforcing whereas 3 spikes seem
> to create phantom spikes. If anything else new is noted in the FAQ, I've
> missed it.
>
> Thanks and Cheers!
>
> Art Russell
>
> Atlanta, Georgia
>
> mailto:artrussell@mindspring.com
> http://Education.gsu.edu/spehar/
>
> What are the facts? Again and again and again - what are the facts? Shun
> wishful thinking, ignore divine revelation, forget what "the stars
> foretell," avoid opinion, care not what the neighbors think, never mind the
> unguessable "verdict of history" - what are the facts, and to how many
> decimal places? You pilot always into an unknowable future; facts are your
> single clue. Get the facts!
>
> - Robert A. Heinlein, from "The Notebooks of Lazarus Long"