dark skies and Black Magic camera

I filmed the Northern lights on the Sony VG900 , the link is here:

but although i was happy with the low light capability it wouldn't auto focus with a full frame lense.
So Im thinking about the BMC , does anyone have any test footage with either the northern lights or just a dark sky? Or maybe some other faint light like bio luminescence?
I've always thought the best way to test a camera is point it at a dark sky and count how many stars you get without noise.

The BMCC is alright in low-light, but it's by no means an "as-good-as-no-light" camera. I don't think the BMCC would particularly excel at shooting northern lights... The 5D Mark III with a fast lens may be a better option.