[MortonH]

Without wishing to generate a highly technical discussion, what's the approximate maximum exit pupil for reflectors? As I understand it, there gets a point where the central obstruction becomes 'visible' and therefore the exit pupil is too wide.

Specifically, I'm interested in how this applies to my 8" f/6 Dob or a 10" f/5 Dob (which I may own in the future).

I'm wondering about something like a Vixen 42mm LVW, which on the 8" would give an exit pupil of 7mm (and a field of 2.5 degrees) but on the 10" f/5 would give an exit pupil of 8.4mm. Would this be too much?

Answers in plain English please!

Thanks

Morton