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You still have it wrong Chris.
Your 8" f/5 [200mm] dob has a focal length of 1000mm.
1000mm focal length divided by 200mm mirror diameter = 5 hence f/5.
14"[355mm] has a focal length of 1600mm.
1600 divided by 355= 4.5 hence f/4.5, so the 14" has a 60% longer
focal length than your 8", and so will allow only much shorter exposures than the 8".
You are right about the 6SE; at f/10 it is very "slow" photographically.
The 14 would gobble the light up compared to the 6SE, and as you say
with much better resolution.
raymo
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