modded cannon & m66 vignetting

[mindburner]

managed to geta few subs (40x 2 min with bias, flats & darks) if m66 group last night in poor seeing conditions. I was surprised I had such bad vignetting though. I think it is either the

vixen flip mirror or

my homemade 8v 7808 camera PSU,causing this (unlikely)

or the flats - not good enough

shorter exposures of the ring nebula came out better

[mindburner]

actually from omitting my flats, it seems these are the issue