Image Erection / Pentaprism Question

[Larry Rutledge]

I was researching (with my extremely limited knowledge of optics) the double porro prism and pentaprisms for an image erection system (you know, to turn the image 180° in a 35 adapter).

Anyway, I came across this little beauty:

http://www.surplusshed.com/pages/item/l2017.html

and wondered if this would work for me or not. I mentioned some sides being polished, some being ground and needing polish, etc, etc... I, unfortunately, don't know enough about optics to know if this will just work or if I need to do something to it first.

I also found these on there:

http://www.surplusshed.com/pages/item/l3125.html
http://www.surplusshed.com/pages/item/l2140.html

Would either of these work? Perhaps even better?

Thanks for any help,
Larry

[HansK]

Anyway, I came across this little beauty:

http://www.surplusshed.com/pages/item/l2017.html

and wondered if this would work for me or not. I mentioned some sides being polished, some being ground and needing polish, etc, etc... Nice find. Not familiar with polishing high quality glass. I've had my windshield polished with a cerium oxide product. It looks like similar mixtures could be used for you application: http://www.metall.com.cn/cepp.htm I would worry that unless you got a perfect polish you would see the imperfections in the image. Btw - The pentaprism is a cool piece of glass. But the roof pentaprism may be better since it reverses the right-to-left problem. 35mm cameras use them: http://en.wikipedia.org/wiki/Pentaprism

[bikefilms]

I get an image erection just thinking about it.

-a