Quote:
Originally Posted by toryglen-boy
Hi there!!
good polar aligment will allow you to have exposures up to around 2 mins, well i have found that from my experience. i drift align, but i doubt you could do that with this setup
maybe someone else will chime in.
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Hmm - well it depends doesn't it - on the image scale you are using and if you are guided or not. In my case I am unguided and looking to image at 4.5"/pixel at worst, more often half 8-9" that thus assuming I can tolerate up to 2 pixels of movement in an exposure before I have to can the frame I can tolerate 20" of error using a lens - or 10" for the scope.
Now I wonder how closely aligned do I need to get to ensure my rate of drift is less than that for a 60s or 120s exposure, and can I do it? I realise the drift rate will vary with DEC of the target....I did not think I would be that far off hence my doubts about the RA drive speed...