Thanks for the detailed reply,very good information. I know that the limiting factors are the exit pupil and the size of the lenses in the erector tube which are plenty big if they can handle the diameter of the light passing through them.
The question that I have is this, do the larger lenses of some 30mm scopes allow for a larger sweet spot? I know that the optical properties of lenses tend to be better toward the center and poorer toward the edges.
Perhaps it is poor analogy but tennis rackets work fine whether they are regular sized or oversized. But many players pick an oversized racket because it has a larger sweet spot and keeps a ball further from the edge.
Last edited by ruraldoc; 08/14/15.
