Clouds cleared. One night only. Thanks for all the suggestions.
Added the new adapter which reduces metal the back distance for the reducer to within a few mm of correct. OAG camera focal distance thus reduced and at a fixed point with another adapter rather than helecoid.
Assembled OAG /camera/ reducer with some rotating and firm clamping before mounting as suggested.
The result is better and not too bad for 20 minutes of each filter. So perhaps worthwhile collecting more data and trying several hours along with ordering a safer wider adapter from Joshua.
I am still unsure about length of exposure and think perhaps I could double each to 4min. Particularly red which seems very dark in all subs. The attached has some of older Ha subs (with a bit of moonglow ) to boost the red. Any more suggestions gratefully received . In the dark really. Ha.
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