Did you test any Opticron products? One of their recent 8x32 models claims 19mm of ER, and yet I cannot see the entire field with my glasses.
Hi Bill, I have tested some Opticrons, but personally not 8x32.
If you refer to the "Traveller BGA ED 8x32" model, my formula indicates that there should be no problem, because now I imagine that the declaration is "slightly" overrated.
I tested the
10x32 version for which Opticron declares 17mm, but in reality I measured the exit pupil at
14.1mm from the outer glass of the eyepiece and for that distance, the formula still indicates the sufficiency.
So, with my domed glasses I can see the entire all field of view (or the entire observation window of the binoculars), but only if I perfectly center the pupils with the correct IPD.
In fact, it will always be possible in other situations, to have some degree of restriction (as in your case).
The "Traveller BGA ED" model is a good-excellent binoculars for the price and has an field of view average wide (eyepieces with 65 ° AFOV), so if the loss is only a few degrees, it always remains an good vision and it's still an excellent choice.
If, on the other hand, we want to be a little more rigorous, the Opticron guys should be scolded for this statement to the limit of acceptable.
The same can be said for all competing Traveller binoculars, such as the Kite Lynx, Nikon M7 and HG new, Maven B.3 or all other similar 8x-10x30, with ER subtracting up to 10% of the field of view (whit higher price).
In this case my formula immediately evaluates the ER of the eyepiece as "too short" for the glasses (insufficient). Here the statement is honest! (I have tested Lynx and M7 10x30)
And despite the fact that the AFOV is greater (69 °), the loss with glasses will be greater, and the same final vision will be equated (about 63 ° AFOV).
and yes, AFOV is certainly playing a role, imho
The math is not an opinion! AFOV is certainly and undoubtedly playing "the" role. :t: