Okay maybe I am missing something. How can two binoculars with the same exit pupil have different fields of view? Probably a very basic question but I can't understand it. I would think that to have more field of view in the same sized circle you would have to decrease the power? Zoom in zoom out see more see less. How does this really work. I am no physics type so can someone give a layman explanation?
I am sure that one of the more well versed optics nuts on here could give you the specifics but I believe it is the eyepiece design that largely determines the field of view. It really has nothing to do with the exit pupil.
Never thought about it till now, but I think Frank is on the money. If you were to add a long tube to each "ocular", you would severely affect FOV, and for that matter light gathering and reflection.