hi friends,
this is a result of 2 nights.
transparency was regular, but seeing was very differing again.
the borderline of clear skies and clouds/upcoming front was too close to my place.
so seeing was not at its best, varying from FWHM (focus) 1.8 (rarely) to 4.0 arc seconds !
mostly I had around 2.5 only...
(watching the guide-star was somewhat funny: changing its shapre from pin point to snowball...too bad)
I intended to operate the scope at f/18 with the barlow,...no chance, yet...
I took different exposures for luminance in terms of exp-time:
2 min, 4 min and 8 minutes.
also, since I collected almost 2 hours of 2x2 binned RED, I used this fr the outer shell as an additional layer to lum, to enhance what was not there...(-;
all data and all imegs including the enlarged crop is here please:
http://www.stargazer-observatory.com/m57.html
thanks for looking guys,
Dietmar