To what degree,if any, does interpupillary distance affect the field of view of binoculars? Thanks.
It doesn't affect the FOV at all.
The aperture stop in the EP sets the AFOV and with the magnification that sets the FOV.
At very close distances, a small IPD will reduce the overall FOV, but with the advantage of accomplishing greater overlap between what is seen by the left and right eyes.
--AP