porro prism camera lens?

I have a carl zeiss 8x30b monocular which could be used on old contaflex cameras as a 400mm manual focus lens. To this day the 8x30 zeiss line is considered an excellent line of birding binoculars. They are said to work great on cameras however you have to clean the yellow oil residue off of the prism in some cases from what I understand. Anyways I was wondering why we don't see modern porro prism camera lens? They allow extremely compact and lightweight capabilities in comparison to groups of stacked lens elements. I know that many camera viewfinders use a porro prism so I guess that is a start. does anyone have input on this?

I'm not sure why you would want a porro prism in a camera lens unless you wanted to jog the lens sideways. The other reason would be to preserve the handedness of the image but this isn't necessary since the readout direction of the sensor already corrects this and the viewfinder already does this itself for composition.

What are you trying to achieve by adding a porro prism? Your monocular is small because it is a 400mm f/13.3 lens, not because of the prism. The prism was so that the image wouldn't appear inverted in the eyepiece.

If you look at the ray path in a porro-prism binocular, you'll see it is in fact folded up, shortening the total length of the system. I'm not convinced it would save any weight though, as the prisms would be added to save a few elements.

macroimage wrote in post #15397192
I'm not sure why you would want a porro prism in a camera lens unless you wanted to jog the lens sideways. The other reason would be to preserve the handedness of the image but this isn't necessary since the readout direction of the sensor already corrects this and the viewfinder already does this itself for composition.

What are you trying to achieve by adding a porro prism? Your monocular is small because it is a 400mm f/13.3 lens, not because of the prism. The prism was so that the image wouldn't appear inverted in the eyepiece.

Ok that makes sense, I didn't realize it was an f/13 and I thought the prism did all of the magnification. Thanks for clearing that up. here is a picture of the setup in action http://en.wikipedia.or​g …ex_superB_Zeiss​_8x30B.JPG