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Re: (IAAC) astrophotography
Clouseau,
I too have recently started with a little astrophotography, and have had
a mixed success. I will explain here what I have done so far, what sort
of results I have obtained and what I think might make it better. I
don't feel as though I am in a position to 'instruct' you on taking
pictures, but you can at least see the problems I have had.
I own a 200mm f/5 Newtonian, which, although not permanently mounted, is
equatorial. It has on it a piggyback mount, which you should be able to
pick up form any astro outlet, or maybe camera shop. (Piggybacking is
simply fitting the camera onto the tube of the telescope, using the
scope as an elaborate drive: it serves no optical purpose). I have a
screw-fit Zenit SLR camera, and adaptors for prime focus and eyepiece
projection photography.
The main problem I have when taking photos of any exposure is driving,
since my scope is never accurately aligned. This however should not
affect any piggyback pictures you take, as it is possible to drive the
scope, and so the camera, simply by looking through the eyepiece. With
a smooth hand, this can lead to some pretty good results.
As for taking prime focus or eyepiece projection exposures, we are
limited very much by the inaccuracy of the drive, or rather the lack of
polar alignment. If you use a fast film and set the drive going though,
you can still produce some reasonable results with exposures of around 1
minute. In many ways, I have found it really is pot luck whether an
exposure comes out as a sharply focused image or a hopelessly blurred
squiggle of lines caused by vibration and and driving inaccuracies. It
would seem that for really good photos through a scope, permanent
mounting and good polar alignment is essential, but we can at least try.
I hope this has been of some use. Some of my results can be found in
the "recent observations" page of my site below, although they have not
scanned particularly well. I wish you the best of luck, and hope this
has helped in some way.
Clear skies,
Paul Haworth.
'Space is very big.' - inspiration from Douglas Adams.
http://www.geocities.com/CapeCanaveral/Hangar/9499/index.html
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