Re: Graticule for Leica stereo eyepiece

JB writes:

Richard, I am not sure it is as simple as that. That is why I am
asking. I already own the Leica 10x/21B and 16x/14B eyepieces. The 10x/
21B actually has a field of view of around 21mm. And with this logic
the 16x/14B should have 14mm. BUT..., actually placing a paper scale
inside the 16x eyepiece at the position where the graticule is
supposed to be reveals a field of view of approximately 18mm! A 12mm
graticule therefore only covers 2/3 of the field of view and not 12/14
as expected. This was a surprise to me. So if anyone could actually
check out the 25x/9B I would be very greatful.

Just measure the field stop.

Magnification times field number should be about 220.

An 18mm field on 16x equals an enormous 60 degrees field of view. Is it
really that wide?
.