Quote:
Originally Posted by pmrid
The first thing that struck me about these reflections is that they all appear to be very similar in terms of their radius and number of 'lines/elements' in them. If they were induced by out-of-image stars, I would expect more variability in both. Another possibility you may like to investigate is that the light is not coming from in front, but from behind the scope - most focusers' draw-tubes have a clearance of varying width between the tube and the body of the focuser. If light was shining towards the back of the scope from behind, some would find it's way up the drawtube and be subject to reflection back to the imaging plane off the back surfaces of - whatever.
Since you found the artifact did not appear in an image where the scope was pointing south and a fair way off vertical, it may be worth looking at where your laptop screen was pointing and any other light source behind the scope.
Just a thought.
Peter
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Thanks for that Peter. In terms of the laptop, I have it sitting in the south-east corner of the observatory. So for M42 and Horsehead, the laptop would definitely be behind the camera. I do however, have a sheet of acrylic (red) covering the screen, but maybe there is some bleed off to the side. Definitely worth investigating further.
One thing that probably does not help, is that the interior of the observatory is cream colourbond. On my list of items to complete is to purchase some black cloth or something similar to line the walls.
Cheers,
Daniel