I unscrewed the clamps a little on the primary, re-checked the collimation and gave it another go a few days ago. It seemed to have improved, although not sure if it's 100% the same as it was before or not.
I'll show you how it looks John at our next meeting and you can tell me what you think
Although I'm starting to think I may also have a not-so great primary mirror from Meade now when comparing the image of M42 against my previous 6" dob. If my memory serves me correct the image in the 6" showed more detail (not brighter) than my current 10", which clearly shouldn't be the case. I'll have to compare it against your 12" John too
