No probs
The Orion pic is a full RAW straight out of the camera. No processing. Dont forget your looking at a compressed Jpeg, I can assure
you that the full raw is very smooth , but also, its a 20 second exposure not a 5 minute or a 10 minute. I haven't done any prime imaging at F10/F7 yet, so I don't have much of a reference regarding noise at that length.
Have a read through this , it might help you
https://www.google.com.au/url?sa=t&r...GoyblZ9LxtguFw
I was in your situation
however we all have different requirements.
I considered the 6D but it had just been released and was a further $600 dollars on top of the 60Da price. Plus the full frame wasn't suitable with the hyperstar lens with the largest usable sensor diagonal dimension being 27mm.
The 6D is a way better camera and if you want to do mainly nightscapes then It would be the way to go. But if you just purely want it for asrtophography and no daytime shots, @ 2K plus, I'd start looking at CCD camera's