>On Mon, 13 Nov 1995, Bob Neuman wrote:
>
>> I think you may be referring to a door security fisheye peepsight, which
>> can be mounted in a LENS cap, and then on a lens (be careful that the
>> rear of the peepsight does not contact the lens front element) to make
>> an inexpensive (though, alas, poor) fisheye lens. It is worth doing,
>> given the low price, to gain experience with a fisheye lens (some of us
>> love to use the durn things...).
>
>Finally! Some knowledge!
>
>Have you tried this? Would it work if I put it on a body cap .. or if on
>a lens cap, just what sort of focal length would be good? Thanx! :)

I did it years ago (when you're desperate, you're desperate!). Does
not work on a body cap - a lens is needed for imaging. The longer the
focal-length, the larger the image, but it will be empty magnification -
the very small image you get by putting it on a 50mm lens may be better
looking because at least the large grain is sharp when the image is
enlarged a bit. Don't let me discourage you - the images are fun,
and it is a good way to see what fisheyes do.
David Ruether