20X100 25x100 Binocular

Ed and others,
I think we have to keep in mind that looking through the objective and
through the eyepiece are not inverses of each other.
observing through the eyepiece, the light must come into the objective in a
parrallel bundle with a very small angle relative to the optical axis.
looking through the objective however, light may come through the eyepiece
from many different and large angles some of which do not occur in the
previous situation.
I feel that the D shaped exit pupil viewed from one edge of the objective is
really irrelevant as far as percent obstruction of the exit pupil goes since
the light from the other edge of the objective still passes through the
supposedly invisible portion of the exit pupil.
my 2 cents,

anton

Ed and others,
I think we have to keep in mind that looking through the objective and
through the eyepiece are not inverses of each other.
observing through the eyepiece, the light must come into the objective in a
parrallel bundle with a very small angle relative to the optical axis.
looking through the objective however, light may come through the eyepiece
from many different and large angles some of which do not occur in the
previous situation.
I feel that the D shaped exit pupil viewed from one edge of the objective is
really irrelevant as far as percent obstruction of the exit pupil goes since
the light from the other edge of the objective still passes through the
supposedly invisible portion of the exit pupil.
my 2 cents,

anton

I feel that the D shaped exit pupil viewed from one edge of the objective is
really irrelevant as far as percent obstruction of the exit pupil goes since
the light from the other edge of the objective still passes through the
supposedly invisible portion of the exit pupil.
my 2 cents,

anton

Think about what you just said, Anton. You have a "feeling" that something is
so. Feelings are nice to have, but don't always properly describe physical
reality. People used to "feel" that the world was flat. They could not imagine
standing on a sphere.

In any case, your type of argument allows manufacturers to exploit the amateur
community. There is a saying among the less scrupulous: "they will never know
the difference".

Good luck out there,

RC

I feel that the D shaped exit pupil viewed from one edge of the objective is
really irrelevant as far as percent obstruction of the exit pupil goes since
the light from the other edge of the objective still passes through the
supposedly invisible portion of the exit pupil.
my 2 cents,

anton

Think about what you just said, Anton. You have a "feeling" that something is
so. Feelings are nice to have, but don't always properly describe physical
reality. People used to "feel" that the world was flat. They could not imagine
standing on a sphere.

In any case, your type of argument allows manufacturers to exploit the amateur
community. There is a saying among the less scrupulous: "they will never know
the difference".

Good luck out there,

RC

"anton jopko" wrote in message ...
Ed and others,
I think we have to keep in mind that looking through the objective and
through the eyepiece are not inverses of each other.

I feel that the D shaped exit pupil viewed from one edge of the objective is
really irrelevant as far as percent obstruction of the exit pupil goes since
the light from the other edge of the objective still passes through the
supposedly invisible portion of the exit pupil.
anton

Anton,
I think a review of all the previous posts will show that no one
voiced skepticism as much as I of the view through the objective. To
prove it for myself, I employed the use of a laser light, the closest
thing I could get to a point source for testing the binocular. I
viewed the image of resultant exit pupil projected onto a white wall.
By doing so, I was able to observe the D shape ( I would refer to it
more of a cat's eye shape, but D is close enough) IN THE EXIT PUPIL.
The laser allowed moving the light source across the face of the
objective to observe the changing exit pupil. The image on the wall
is a real image. The projection is a true picture of the shape of the
exit pupil. Enlarged to 20-30mm, it was simple to observe. Having
seen it and clearly understanding what it was showing me, I could then
observe that the appearance of the exit pupil by looking down thru the
objective showed nearly if not exactly the same thing.

edz

"anton jopko" wrote in message ...
Ed and others,
I think we have to keep in mind that looking through the objective and
through the eyepiece are not inverses of each other.

I feel that the D shaped exit pupil viewed from one edge of the objective is
really irrelevant as far as percent obstruction of the exit pupil goes since
the light from the other edge of the objective still passes through the
supposedly invisible portion of the exit pupil.
anton

Anton,
I think a review of all the previous posts will show that no one
voiced skepticism as much as I of the view through the objective. To
prove it for myself, I employed the use of a laser light, the closest
thing I could get to a point source for testing the binocular. I
viewed the image of resultant exit pupil projected onto a white wall.
By doing so, I was able to observe the D shape ( I would refer to it
more of a cat's eye shape, but D is close enough) IN THE EXIT PUPIL.
The laser allowed moving the light source across the face of the
objective to observe the changing exit pupil. The image on the wall
is a real image. The projection is a true picture of the shape of the
exit pupil. Enlarged to 20-30mm, it was simple to observe. Having
seen it and clearly understanding what it was showing me, I could then
observe that the appearance of the exit pupil by looking down thru the
objective showed nearly if not exactly the same thing.

edz