August 27 2010
Well, tonight is the night when I can finally get my scope out after over two months of waiting for clear skies. The aim for tonight is a little observing, I want to get my first sighting of Jupiter, and to sort out my astro-imaging technique.
The skies are looking promising and after a short sharp shower I take my mount and scope outside to cool. About 9:30 I begin to set up and the start of my nights frustrations begin. I manage to polar align and perform a single star alignment but I cant seem to pick out any of my subjects for tonight. Getting frustrated I check my polar alignment and start again. Still nothing. So I decide to go back to basics and check that my RA scale is set up correctly - low and behold it had moved. After setting polaris in transit and locking in the correct reading on the RA scale I polar align again. After the fourth single star alignment I am still not having any look picking out any objects. In my frustration I decide to leave to observations and try my Astro-Imaging technique.
After balancing everything I attach my D200 to the scope with the dismantled 1.25” eyepiece adapter thus ensuring I have enough inward travel without the need for a barlow. Once all set up I fire off a 120s frame. Upon reviewing on the back of the camera I can see much movement caused by mirror slap. This is despite the use of the MLU function. So, to avoid this, I try covering the scope at the beginning and end of the exposure which works perfectly. Following this I try several exposures of varying length to see how everything performs.
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| © Lee Diggle 2010 |
Once my technique was sorted I tried several frames with my camera piggy backed onto the scope. I managed to set a semi decent shot with part of Cassiopeia in frame. However there is a large amount of light pollution visible so in the annotated shot I converted to B&W.
After this attempt at widefield I focussed on the Moon with a view to taking a single frame shot of the entire moon through my disassembled 1.25” eyepiece. I decided to take several shots a varying focus point to ensure at least one shot is perfectly focussed. In the end I ended up using 1/400th s
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| © Lee Diggle 2010 |
After this attempt at widefield I focussed on the Moon with a view to taking a single frame shot of the entire moon through my disassembled 1.25” eyepiece. I decided to take several shots a varying focus point to ensure at least one shot is perfectly focussed. In the end I ended up using 1/400th s
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| © Lee Diggle 2010 |
Following this Jupiter was in view so I turned my scope over. Firstly to view with my 32mm EP working my way up to my 9mm EP and 2 x Barlow (267x mag) The views were good with the SEB clearly visible along with three moons - Ganymede, Europa and Io. Originally I was just going to observe but decided to try taking a photo. I was surprised at how fast a shutter speed I needed to retain detail in the surface. The shot below is taken at 1/40th s.
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| © Lee Diggle 2010 |
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