|
Greg i believe carbon tubes for refractors is just a design fad and not justified. It also makes heating an objective, to prevent condensation, more difficult.
I agree there are many excellent choices in your size range and going for the best published specs, rather than buying for a name, makes sense. Most APOs in that size range have pretty good imaging circles with flattened or reducer/corrector. I consider corrector mandatory as they increase speed. If your worries about lost of some focal length with a corrector, just buy the next size up imho.
|