Pinhole Cameras

I posted this for my reading group, but figured some of you might have some thoughts...

I don't know how many of you are familiar with/have experience with photography, but I was thinking about this last night, and I think it might make for some good theoretical discussion. So what is a pinhole camera?

What this picture fails to show is the "light-sensitive" or photography paper (note here that not only the object, but also the paper, must be "able to be 'photographed'") that is taped to the inside of the canister on the edge opposite the pinhole. Here's another image that might help:

This is probably all old news to most of you, but I thought I'd post about it just in case. In a dark room, you place a piece of paper at the back of the canister and hold the shutter (the index card in this case) shut as tightly as possible. Then go outside, find something you want to photograph (light write), open the shutter, and hold the pinhole camera as steadily as possible for 10-12 seconds. You then take the "photographic paper," as I would like to call it, and process it with chemicals. This is what, at least in part one of Camera Lucida, Barthes seems to imagine as the paradigm, or model, for how all photography works.

What I notice when I look at this image is the extent to which it parallels what happens with the human eye, at least at an elementary level. Our eye is the pinhole which prohibits a profusion of light, focusing on just one point, and allowing that filtered (according to postition) light to then create an (upside down) image. And this pinhole, as I see it, is also the perfect model for Barthes' punctum. But if we are to take the pinhole camera as an elementary model for how we see at all, what becomes the human parallel to the photography paper? Are our brains, out of necessity, "photographic"? When we see an image, what do we see it on?