[Leica] binoculars - looking for assistance

[marcsmall at comcast.net (Marc James Small)]

At 09:20 PM 1/19/2007, G Hopkinson wrote:

 >Roof (Dach) prism binoculars
 > Roof prism binoculars are becoming popular thanks to their light
 >weight and compact size.
 >Since production and adjustment of roof prisms require the highest
 >level of precision, optical performance differs from maker to
 >maker. "Roof" refers to the roof-like shape of the prism. While,
 >"Dach" is taken from the German word for "roof."

Thanks, Hoppy.

The Japanese industry occasionally does this sort 
of thing, as they do appreciate German 
engineering.  To most of the world, including 
Europe, these are "roof-prism" binoculars.

All optics is a matter of 
compromise.  Porro-prism designs in the end allow 
a greater control over optical 
aberrations.  Roof-prism designs allow smaller 
and slimmer designs.  Most of my own binoculars 
are Porro-prism designs but the later ones are 
generally roof-prism glasses.  Use of aspherical 
lenses, while most expensive, allows some 
incredible performance from roof-prism glasses 
but these are no longer commercially available to 
my knowledge.  (Did you just win the 
lottery?  Then contact Zeiss, Leica, Nikon, 
Pentax, and Leupold, and put in our bid.  You 
will be pleased at the result but not at the charge!)

Marc


msmall@aya.yale.edu
Cha robh b?s fir gun ghr?s fir!