I just got back after a round of testing the new Nikon 7X50 and 10X50 WX, conducted at the retail shop, Focus Scientific, here in Ottawa. My principal interest was the 10X50, for obvious reasons. There's a fair *chance* I'll go back again tomorrow, so if you have any specific points needing addressing, ask away.
In a word, WOW!
They meet my expectations, based on published info. That is, there were no surprises at all. Including the fact that the published figures for the AFoV understate reality notably, due to their being merely calculations.
Using the flashlight-through-the objective test, which projects a circle of light as defined by the field stop, I measure AFoVs of:
7X50, 71 degrees
10X50, 85 degrees
These figures should be correct to within about 0.5 degree.
It goes without saying that they utilize the full aperture on axis. But the circle of full illumination is quite small. But that's absolutely OK! A baffle, which appears to be within the prism system, is sized so as to provide maximal stray light suppression without impinging on the axial light cone. This is a very good strategy; it mirrors my own preference in my home-made binos.
False exit pupil segments, or 'fingernails' as we like to call them, are a NON ISSUE. There are two, but even the worst is such a tiny sliver as to be of practically no import... IF it were to be sufficiently near the principal exit pupil, that is. But nope, these pupil segments are well and safely removed from ever falling upon one's iris.
The region surrounding the exit pupil is agreeably dark when the instrument is pointed up toward the daytime sky. Which means that unless direct ingress of a quite bright light source illuminates the interior walls and prism/lens edges, this source of scatter to reduce contrast is vanishingly small. I should conduct some further testing under extreme conditions to explore this further, so as to divine just what surfaces would be illuminated and how near/far from the exit pupil they lie.
By *visual* comparison of an illuminated surface seen directly and through the the bino, I *crudely estimate* a transmission in the neighborhood of 90-ish percent. I could detect a slight dimming, which I feel must preclude a transmission of 95+%. But do note that such visual comparisons are fraught with the potential for illusion. If I can rig up an add-on tube for my SQM in time, I'll strive to obtain a much more reliable measurement, which I should think will have an error of no larger than about 1%.
More to follow... (I'm afraid of losing my work on this phone. )