Chuck & Kim

I saw your post that mentioned roof prisms. I had never heard the term so I decided to google up some information. There are tons of sites talking about roof prisms and two that I thought might be of interest are included  here:

 

Roof physics
http://www.kireinc.com/english/Roof_Prism.htm

 

Comparison
http://www.birdwatching.com/optics/roof_vs_porro.html

 

After reading several articles, I am not sure how roofs differ in appearance or construction from the Porro. The roofs look just like the prisms I had in and old pair I once had.

 

Jim