Getting back to the article by Damian Peach further back on this thread, it clearly seems to me that most have not paid much attention to it or am I wrong?
I realise that the images and comprisons are examples of perfect conditions(and are stacked and manipulated captures) with all necessary criterias met etc., but it is NOT the central obstruction that causes loss of fine details.
The main conclusion is what some have mentioned here : APERTURE .RULES...................end of story.
After some more Googling, let's now go back to the 12 inch Meade SCT I have been considering along the way :it has all that is required for planetary viewing : large aperture , large focal ratio so I don't need to barlow the crap out of it(talking about extra optical surfaces!)and high quality aberation reduced optics all in a compact tube and not an F7 or F8 long ,heavy, wind catching cannon.
Central obstruction????...............rated at 11.1%..........shocking!....ain't it???.............I'm sure that a newtonian with an average obstruction of usually more than 20% is muuuuuuuuuch better?
I appreciate the help of all and am grateful
..........but c'mon everyone...........let's keep the ''myths'' at bay next time as I have been confused to buggery
!