Comparing to my 14" Dob/Newt to my smaller refractors
How to say this without getting into terminology hair splitting is for me difficult. In my 14" Dob/Newt I have a much better spread of larger exit pupil (using my 3.5mm ep I still have about 0.75mm exit pupil, in my 128 refractor it is at ~ 0.74 using my 6mm ep). It is a different aperture difference than 8" to larger but I hope the points are still valid. I could make a different spreadsheet for an 8" of whatever focal ratio but since we are talking more about aperture i hope it sits well. The three things of interest in comparing here to me are
-exit pupil size (here, Jupiter relative size for magnification used)
-mag/inch of scope used (how hard are my optics being pushed)
-magnification of scope to the sky seeing (what is reasonable to expect)
I'll stick to the 200 to 300 magnification range as that is most often where my seeing seems to sit.
here is the FS128 data
and here is the XX14g data
I hope the data helps make apparent the tradeoff of exit pupil size to the seeing limit, both scopes working to their respective possible resolution (Dawes or Rayleigh) limits at whatever ep is in the focuser as I understand that is based on aperture alone. This I think gets lost in some discussions.
The larger scope has much more to work with, and I welcome the apparent dimming from decrease in ep focal length! I also enjoy trying out various filters of all types as losing apparent brightness not so much an issue as with my smaller refractors. This to me translates to a larger presentation of Jupiter under the potential seeing limits I usually experience.
What is interesting to me also is that as the 14" Dob/Newt is working at a higher resolution, seeing conditions are also more likely to impact, if that makes sense. So I have a potential larger undimmed view of Jupiter that has a higher potential resolution than is possible with the smaller scope.
An explanation about the aesthetics of the view is that the smaller scope can work in it's upper magnification range (before dimming undesirable) as it is going to less sensitive based on it's resolution (object view becoming 'fuzzy'). The larger scope will always be working at it's resolution, but the presentation can be much larger - and it's no problem dropping down the magnification to where the fuzzyness can dissipate though Jupiter can appear uncomfortably bright.
To me it helps explain why some people may be entirely happy with the view through a smaller scope, and I am in that group, I feel they never really disappoint. The larger scope has far more potential, can be 'dialed in' to a much finer degree, and will have a larger presentation of the planet possible, which I also really like, so count me in that group too.
If anyone insists on comparing at same size exit pupil we go back to the large scope is still working at a higher potential resolution so I am not sure that really makes sense or is fair.