Re: (IAAC) Orion Natrium Filter

• To: netastrocatalog-announce@latrade.com
• Subject: Re: (IAAC) Orion Natrium Filter
• From: Owen Brazell <owen@online.rednet.co.uk>
• Date: Fri, 29 May 1998 18:41:03 +0100
• In-Reply-To: <9805281906.AA31764@trillian.dev.latrade.com>
• References: <Your message of "Thu, 28 May 98 15:01:45 EDT." <9805281901.AA03874@trillian.dev.latrade.com>
• Reply-To: netastrocatalog-announce@latrade.com
• Sender: owner-netastrocatalog-announce

The filter that Yann is referring to is a broadband filter made by Orion
Optics UK and from my brief look at one of the early ones is a complete
waste of money. Their EHC filter is not too bad. Natrium as you suggested
is a corruption of the latin for sodium. Stear well away from this one Yann

At 15:06 28/05/98 -0400, you wrote:
>
>Oops - come to think of it, it's more likely these "Natrium" filters BLOCK 
>sodium than narrowly bandpass it... After all, at least in the US, much of
the 
>artificial skyglow derives from sodium-vapor (Na emission) lighting. Is it 
>possible that "Natrium" is Orion's European name for their "Ultrablock"
filter 
>(similar to the Lumicon "UHC" filter)?
>
>Lew, awash in emission lines
>
>
>
>

• From:
• Re: (IAAC) Orion Natrium Filter
• From: Lew Gramer <dedalus>

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