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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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