Quote:
Originally Posted by DiscoDuck
This
http://www.innovationsforesight.com/...r-is-too-much/
gives some interesting rule of thumb estimates for guiding accuracy required for rough star roundness, i.e. 0.5" RMS for 2" seeing.
In general, a back of the envelope calculation shows that if you want to limit to an x% increase in FWHM in any direction, your RMS guiding error should be no more than about sqrt((1+x/100)^2-1)/2.4 times the seeing. So to limit to a 50% increase you'd need RMS guiding at about 0.5 times the seeing (1" in the above). 10% would require 0.2 times the seeing (0.4" in the above).
I'd say at 0.45" you're pretty good, Suavi!! 
Personally, with my EQ6 (belt modded), I got the best I've ever got the other day, and that was still about 0.7" RMS. I'd be ecstatic to get a guiding graph like yours!!  Not too sure why I can't get better. |
Thank you Paul for the link and your explanation.
My mount tracks okay, but I can see some degree of star elongation in some/most of my 15-minute subs. Some subs are nearly perfect though. I can live with slightly elongated stars, but what it means is that images are not as sharp as they could have been and probably overall acquisition time could be shorter with more precise guiding, because photons that should land only on one pixel are instead distributed over neighbouring pixels too, leading to a weaker signal. Saving for a better mount will need to take some years though...so in the meantime I will thoroughly enjoy the gear I currently have!
Quote:
Originally Posted by Eden
Slawomir have you looked at PEC training at all? I've seen some improvements though the AutoPEC feature in EQMOD and I believe others (Barry?) have had similar success. Might be worth a try if you've not already.
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Hi Brett,
Thank you for pointing that out and yes, I tried PEC training but with mixed results. However, since I need to move my gear in and out of the house, I found PEC not being very practical in my case.