(Theo Ker) wrote in message . com...
So if that is true, what would be the difference for me when switching
from a 20x60 oberwerk to a 20x100 miyauchi fluo? Nearly none???? Hard
to believe!

TK

Theo,

Well first it would be necessary to isolate the influence and obvious
benefit of jumping to flourite lenses. The benefits due to increased
contrast and reduced aberations could be substantial.

Another important aspect of this comparison would be to clarify, are
those the pre-2003 Oberwerk 20x60 or the new 2003 version with
significantly improved coatings. I've already written a short paper
on the differences in Oberwerk coatings old vs. new and have hours of
testing to prove the substantial benefit. There is about a 0.3 mag
difference between the coatings in the 15x70 size old. vs new. The
old 15x70s perform at a level just below Pentax 16x60s. the new 15x70
are getting closer to performance (but not quality) provided by
Fujinon 16x70s.

So, looking at the pieces you would get 0.3 mag gain over older
version of coatings to newer, 0.3 to 0.4 gain from 60mm to 100mm and
I'm guessing maybe another 0.3 gain by going to flourite. That's a
total of 1 full mag gain. That would be outstanding.

To get that kind of gain from any other changes, you would have to
increase magnification in 10% increarments by a factor of 6 or 7,
or have skies imprve by a difference of at least mag2 in Naked Eye Lim
Mag.

If you've got the newer version of the Oberwerk 20x60, your gain would
be more on the order of 0.7 mag. Even an increase of 0.7 mag would
allow you to see more than twice as many stars in an equivalent fov.

Maybe you thought at first glance that the data doesn't support your
personal experience, but I think it supports it very well. Of course,
you haven't stated what Lim mag you've reached with either binocular.

I have answered arguments already from several individuals on differnt
forums that each have posed a very unequal situation as basis of
argument. When you take the problem apart and look at all the pieces
the answer is always right there.

edz