In my last post, when I described binoculars, I mentioned two 90-degree
bends at right angles to each other. Traditional binoculars actually have
two 180-degree bends, each consisting of two 90-degree bends in a prism. It
is correct that there are two 45-90-45 prisms in each side, and these are
oriented 90-degrees with respect to each other (around one axis of
rotation). But they are also 180-degrees with respect to each other around
a different axis of rotation, and the total number of reflections in each
half is four rather than two. Sorry if I confused anyone.
If you do not understand how binoculars work, it is best to view a picture
in an encyclopedia. It also helps to buy an inexpensive pair of prism
binoculars that you would be willing to dismantle (permanently). I do not
recommend dismantling binoculars if you intend to reassemble them and use
them. You would want a clean room and alignment jigs.
Michael D. Edmiston, Ph.D. Phone/voice-mail: 419-358-3270
Professor of Chemistry & Physics FAX: 419-358-3323
Chairman, Science Department E-Mail edmiston@bluffton.edu
Bluffton College
280 West College Avenue
Bluffton, OH 45817