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Limits of an 8" Dob
I took delivery of a new crop-sensor Nikon DSLR today. Chucked on the 1.25" 2x Barlow T-adapter, plugged it into my 8" GSO Dobsonian and got the first photo below, of Jupiter & the four moons. It was the clearest of about 10 shots I took, edited a little to clarify details.
I've taken images of Jupiter before with full-frame cameras (second image below of Venus Jupiter conjunction); though this one was significantly bigger in the viewfinder, it's actually not any clearer.
My expectation is that I've met the resolving limits of either the Dob's optics or the cheap Barlow. Or maybe that's about as good as Jupiter gets with a single exposure.
I was thinking of getting some tube rings & dovetail etc to put this thing on the NEQ6 I just took delivery of, but this photo largely convinced out of it. Its focuser doesn't allow camera use without the Barlow, so if this is about the level of detail I can hope for then it's not worth bothering... is it?
Can someone say definitively that this is about as clear as the GSO 8" f/6 mirror gets? I kinda wouldn't expect it to do better than this for the amazing $500 price tag - those moons are like 10,000km across and about 600 billion km away; to me it's astonishing it can resolve them at all.
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