Quote:
Originally Posted by ZeroID
Check your polar alignment first obviously, I thought I was pretty good till I did my little exercise in rotating long exposures. No almost no guiding required and almost zero drift. Thread here if you're interested. My symptoms were identical to yours.
http://www.iceinspace.com.au/forum/s...d.php?t=151186 |
Polar alignment is good, 1.1 arc minutes off in Alt and Az. Also remember that the same exposure time in the primary scope has no drift when autoguiding, almost none when unguided, yet it's 2180mm focal length vs the piggyback refractor at 600mm. If it were polar alignment I would expect to see more exaggerated drift in the 2180mm not the other way around.
Quote:
Originally Posted by ZeroID
The other factor could be balance of the mount/scope/counterweight. Do you rebalance when you change scopes over ?
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I never change the scopes over, as in, 6mo+ between any physical changes to the system at all, 4 years since I changed equipment/balance. I have checked the balance and it's OK. But,whether somethings is pulling on the refractor in some direction ..... maybe but can't see it .. must be, but still can't see it
Hmm