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- To: owner-atm@shore.net
- Subject: BOUNCE atm@shore.net: Admin request
- From: owner-atm@shore.net
- Date: Thu, 24 Oct 1996 22:44:52 -0400 (EDT)
>From atm-owner Thu Oct 24 22:44:49 1996 Received: from maxx.mc.net (root@maxx.mc.net [206.138.8.7]) by relay1.shore.net (8.7.5/8.7.3) with ESMTP id WAA20099 for <atm-digest@shore.net>; Thu, 24 Oct 1996 22:44:48 -0400 (EDT) Received: from d1012.mc.net (d1012.mc.net [206.138.11.112]) by maxx.mc.net (8.7.6/8.6.12) with SMTP id VAA20359 for <atm-digest@shore.net>; Thu, 24 Oct 1996 21:44:45 -0500 (CD T) Message-ID: <3270333F.7FF6@mc.net> Date: Thu, 24 Oct 1996 20:25:51 -0700 From: Jack Schmidling <arf@mc.net> Organization: Jack Schmidling Productions, Inc. X-Mailer: Mozilla 2.02 (Win16; I) MIME-Version: 1.0 To: atm-digest@shore.net Subject: Help! on lenses Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit I need some help. Here is the problem... My 10" scope is optimized for use with my 4 x 5 camera. The film plane is only about 1/4" above the shoulder of the focuser unlike 35mm cameras that hang out several inches. This means minimum diagonal, minimum flexure and stress on focuser etc... I recently purchased a Lumicon Easyguider and I posted a review of it on sci.astro.amateur. Basically, it does what it is supposed to do very well but because it was designed for use with 35 mm cameras, I had to move the primary about 3" forward, use a much larger diagonal, make an extension tube for the 4 x 5 camera so it looks like a 35 mm and after all that, it is so far from the tube that the 2" focuser seriously vignettes the edges of the field. The problem is created by the fact that the position of the film plane is dictated by the physical contraints of the off-axis viewer. There is no control over where it is in focus other than sliding the eyepiece out which is exactly the wrong way I need to go. I played around with two Barlows which can not actually be used in the Easyguider as is but found the they only buy me about 10 mm and I need several inches. Question: What sort of lens could I put in the eyepiece and/or the autoguider that would move the focus out that far? Any other ideas? Finally, does anyone have the subscribe to address for the astrophoto mail list? js -- Visit our WEB pages: Beer Stuff: http://dezines.com/@your.service/jsp/ Astronomy: http://user.mc.net/arf/
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