Quote:
Originally Posted by multiweb
TBH at 200% I can't see any noticeable elongation. PE is well under 10min so if it's not in a 10min sub it won't be in a 20min sub. What you're looking at is likely to be flexure between your guider and imaging scope.
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I agree with Marc - i can't really see any elongation at 200% either. If you need to zoom in that far to see it, then is it really an issue? Personally i'd be happy with guiding like that
Nevertheless, is the elongation you are seeing parallel with the Dec axis by any chance? If polar alignment is slightly out, the mount will be making more frequent Dec corrections. When this occurs with my NEQ6 and VC200L (a reasonably heavy setup), i tend to see a bit of elongation in the Dec direction as i find guiding corrections in Dec are not as smooth as RA if I have PHD set to "auto" dec adjustment. For me, i find that if I set to either "north" or "south" dec adjustment instead (depending on the direction of the polar alignment error, which is different for every image session for me as i don't have a permanent setup) then guiding performance and subsequent elongation is much better - just make sure to flip the North-South correction when you do a meridian flip. Dec backlash is possibly the cause here in my case which might not apply to you, but it might be worth experimenting with those settings in PHD anyway if you're worried about it with your imaging runs. Just an idea ...