Okay, I'm curious. I have read somewhere that the SW Mak 180 has a central obstruction of 24%. That would translate to about 40mm. Would that not mean that a 150mm Evostar refractor would have about the same (if not more) light gathering ability than the Mak 180?
And if so, surely one could easily compensate for the lower focal ratio with increased magnification? I mean without losing significant amounts of light relative to the Mak.
Would a similar apparent size for planets in the eyepiece be achievable in the 150mm refractor as the Mak180? I ask because while I'm primarily an observer of the Moon and planets, I think the added versatility od the f/8 refractor might be attractive. Also, a higher focal ratio seems like it would make the Mak difficult to align.