To: atm{at}shore.net
From: "Thomas A Simmons" 
Reply-To: "Thomas A Simmons" 



  Assuming these lenses have (or can be modified to have) a
"C" mount flange, they would be outstanding as an electronic
finder scope, by attaching a low cost surveillance camera.

  As a point of reference, a 50MM F1.8 lens used with a PC164C
gives a 4 by 6 degree FOV, and MAG 8.5 real time.

Tom
Tucson, AZ

Date: Mon, 9 Jun 2003 15:05:18 +0200
From: "Nils Olof Carlin" 
Subject: Re: ATM Heligon Lenses

Ellen Mackenzie wrote:

>> I picked up a batch of surplus Heligon lenses mostly for the glass
>>in them. >

>I have one XR-Heligon 75 mm f/1.1 (from some xray image intensifier
>application - with no iris) - its almost 70 mm aperture would make it
>a stunning RFT eyepiece for a well over  f/10 refractor, I believe,
>mounted in a suitable focuser. The large lens seems to be close to the
>focal plane, and the whole field is visible. I also have a Rayxar 50
>mm f/0.75 (!), but when used as an eyeiece, there is much internal
>vignetting and the whole potential field is not available with one eye
>position.
>
>In general, it is unlikely that a camera lens will work as a suitable
>eyepiece - the design objectives are widely different.
>
>
>
>Nils Olof

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