tornado33
11-12-2020, 03:27 PM
8 x 10 mins ISO 1600 using the EOS Ra and Baader UHC-S filter a "stronger" filter then a LPS filter. Still allows plenty of starlight through, I didn't have to search for a guide star, one was right there after composing the shot. So nice to guide with nice round stars thanks to the coma corrector being in front of the pick off prism. 10 inch f5.6 scope.
Ive been having issues with bright stars not being round, Ive tracked it down to blocking the back end of the scope with a round plug of foam. That seems to cause a nasty air current from the full thickness Sutching pyrex mirror that must be a bit warmer then the ambient air. Removing the plug leaves a gap around the edge of the mirror and the tube allowing air to circulate and the stars become much rounder. Some buffeting from an easterly breeze but not too bad.
Full res. version here.
https://www.astrobin.com/k0ycdn/?nc=user
Sure are some strange shaped nebulae here.
Hand guided as usual.
Scott
Ive been having issues with bright stars not being round, Ive tracked it down to blocking the back end of the scope with a round plug of foam. That seems to cause a nasty air current from the full thickness Sutching pyrex mirror that must be a bit warmer then the ambient air. Removing the plug leaves a gap around the edge of the mirror and the tube allowing air to circulate and the stars become much rounder. Some buffeting from an easterly breeze but not too bad.
Full res. version here.
https://www.astrobin.com/k0ycdn/?nc=user
Sure are some strange shaped nebulae here.
Hand guided as usual.
Scott