Re: New AP scope and more

From: RichA (none_at_none.com)
Date: 10/29/04 

Date: Thu, 28 Oct 2004 22:12:48 -0400

On 28 Oct 2004 22:00:03 GMT, chris1011@aol.com (Chris1011) wrote:

>>>Maybe one day we will have some type of glass to make a color free achro
>doublet.>>
>
>It's called Fluorite and when coupled to a Schott N-KzFs2, it will produce what
>you want - pretty well color free doublet.
>
>Fluorite costs about $1000 per kg in raw form. A 9" blank would weigh about
>4.5kg.
>The Schott mating element will cost about $1500 to $2000 in raw form.
>
>Then comes grinding, polishing, figuring, anti-reflection coating (at ~$400 per
>surface), mounting in cell, making the tube assembly with focuser, dewcap,
>baffles, etc. Some profit for the telescope maker, some money for national,
>state and local taxes, a bit of overhead, etc etc etc. Where do you think this
>will come in at, comfortably?
>
>Roland Christen

More than that, why invest such an amount when you could buy
a 20" mirror for the same price, with near perfect performance?
-Rich

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