(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



(edz) wrote in message . com...

1 magnitude improvement, a factor of 2.5, is about what one would expect

The 100mm is back on my to-buy list and a 60mm Pentax PCF WP is
tempting, but I must be strong! ;-)

The jump from 60mm to 100mm aperture will provide only about 0.3 to
0.4 LM gain.

The jump from 10x to 16x and likewise the jump from 16x to 25x will
provide 0.4 to 0.6 LM gain each.

You will gain more from the magnification than you will from the
aperture. You don't need 100mm lenses in the binoculars to get the
gain.

edz

The views through my 25x100 Burgess Binos are a drasmatic improvement
over the views through my 26x70 Kronos. I thing the purported
relationship between aperture and magnification relative to limiting
magnitude is non-linear, and as aperture increases, it assumes greater
significance. As most of the relationship has been established with
relatively small aperture binoculars, the existing formula makes sense
over that restricted range.

Next month, if the weather cooperates, comparisons by a number of
experienced observers will be done to measure the effectiveness of 22"
binoculars versus a 30". This is scheduled for October 25, and I
expect to report on the results within a couple of days of the event.

Clear skies,
Shneor Sherman