Re: [ATM] Klaas Honders Astrograph

["Richard F.L.R. Snashall" <rflrs@rcn.com>]

Dominic-Luc Webb wrote:
> On Tue, 21 Aug 2007, Bob May wrote:
>
>> What is the power loss difference in the infrared between FS and
>> BK7 glass?  Bet that it isn't all that much.
>
> Actually, the main differences between different glass types
> occur along most of the IR and only a very narrow range of UV.
> How would you like to bet, Bob?
>
> http://www.canit.se/~dlwebb/catadioptric/310schmidt/glass.jpg
>
Actually, a 10 mm thickness of FS has an internal transmission of
 > 80% down to about 170 nm.  That narrow range may be a bit wider.
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