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From: al@qiclab.scn.rain.com (Al Peterman)
Newsgroups: rec.photo,sci.astronomy,sci.electronics
Subject: Re: Power Supplies For Ordinary Cameras in Astronomy
Message-ID: <1991May28.125902.9795@qiclab.scn.rain.com>
Date: 28 May 91 12:59:02 GMT
References: <1991May28.040922.19112@ms.uky.edu>
Organization: SCN Research/QIC Laboratories of Tigard Oregon
Lines: 27

In article <1991May28.040922.19112@ms.uky.edu> ghot@ms.uky.edu (Allan Adler) writes:
>
>I have a Minolta XG-1 which I would like to use to take astronomical
>photographs. I have friends who have telescopes and adapters. But I
>recently became aware of a new difficulty: if a shot is going to 
>require a long explosure (e.g. 90 minutes), the battery in the camera
>will run out before the exposure is complete. Even with somewhat shorter
>exposures, it is desirable to avoid having to buy a battery for every long 
>exposure. 

Get a mechanical camera body for astrophotography.  The exposure meter
does not even have to be operational, since they aren't able to
measure the very long exposures.  For a Minolta mount, try a used
SRT-101, 201, 202 or such.  These bodies are easily available at around
$25-50.  All you really need is a working "Bulb" setting and a locking
shutter release cable.  Open the shutter with the telescope covered
(after aiming) to reduce vibration, uncover the scope's mirror (or lens)
and let it expose.  

Even newer cameras such as the Pentax K-1000 are suitable for this kind
of work, and cost under $120...


-- 
Alan L. Peterman                                   (503)-684-1984 hm
                       al@qiclab.scn.rain.com
It's odd how as I get older, the days are longer, but the years are shorter!