On an evening when the forecast had been for cloudy weather, I had great views of Jupiter and Saturn in moments of good seeing with my 6" f/8 Dob. I used magnification from 46x to 230x, with the best views being at 170x, using a 17mm Plossl and a 2.5 Barlow. As it happened the Great Red Spot was not in sight, and the colors of the rest of Jupiter are very subtle, with some of the bands looking light beige. Saturn showed a bright equatorial zone with a sharp boundary where it got darker away from the bright zone. Cassini's division stood out boldly, as did the shadow of the planet on the rings. I could see a bit of darkness where the C ring was superimposed on the planet, but I could not see that ring against the background sky.
Jupiter and Saturn, Sept. 28
Posted 24 October 2020 - 11:55 PM
I've never seen the c ring with any of dobsonian 6 or 8 inch scopes I have owned but I can see the inner cloud all summer long with my 6 inch but also the 4.5inch and 70mm refractor but Saturn has been really good al year long. Juipter has been good at times but I've seen it better. Just one time in 2002 with my 8 inch dob I saw on only one night more than just 3 or 4 bands and great red spot and . I could see at least 8 bands on Juipter great red spot and festoons. I think if you want to see more than with a dob you need a premium mirror or premium apo refractor or intes mak or Questar 7. The extra might be there for extra detail on very rare nights seeing conditions and proper collimation. I think a good orthoscopic might help as well. I bought a 25mm ortho made in japan once and it definitely out perform an average 25mm plossl on a Gaileo 135mm scope. An 11mm or 8mm tele vue plossl should help to on better nights.