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Old 16-11-2014, 08:58 PM
Tony_ (Tony)
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Join Date: Oct 2011
Location: Melbourne, Australia
Posts: 465
I think the collimation wasn't too bad. There was a liquid on the secondary mirror (this could have affected the optical performance). It wasn't until a few days later when I took the corrector plate off that I discovered the liquid had dripped down from the focuser - it was the lubricant.
I will have to relubricate it at some stage - not sure how.
I wouldn't be surprised if my corrector plate is out - I have the rotational direction close enough, but the first time I took the plate off (a few years ago) I didn't realise there were small spacers in there. These came out and I basically had to put them back randomly - not sure how much difference it makes. This could account for the chromatic effect on some of the stars - but I haven't noticed it before. The lubricant on the secondary mirror wouldn't help.
This image was taken with a CDS canon 60d at about -15C. 90 x 30 secs @ ISO1600. I've had trouble guiding lately so I'm down to short exposures.
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