Hi Paul, nice shots of these two classic objects!
Yes I hear your pain with flex, I still have issues with my setup, even after a couple of years.. done everything... a plate that locks down the guide cam to the accessory plate. Huge 12" paralax rings hold main scope in, 14mm accessory plate.... all is bolted to each other.. no flex in focuser, reinforced area around main focuser.. and so on so forth.. but I'm limited to 4min subs... lucky enough to have a fast newt which helps.
What I'm seeing in your above images is what I was seeing with my VC200L and SX-HX916..
Here's a link to a M83 I did with this setup
http://www.baytop-observatory.com/cc...xies/m83f9.htm
Perhaps it still is the mirror ever so slightly moving.. not a great design. Even if you've had it checked by vixen, have a look... I never assume any thing is done properly these days..
The best images I've seen with this scope is an old SX buddy Manfred Wasshuber.... he did
a lot of mods to it to make it a better performer.
here's his link to what he did to his
http://www.astroimages.at/equipment/equipment.htm
I'm not really paying this scope out but I think Vixen really missed the boat on making this a far better one... the slot has been taken up easily with the new range of RC's in the similar price range, and it's a pitty!
I think the OAG is probably the best way to go... I'm seriously thinking along that path for myself.... to go 10min subs would be just sublime.
All the best
Rich