Pinhole Photography

(This page under construction. Check later for an explanation of what pinhole photography has to do with perspective and geometry.)


Building behind fence. Bigger version, in jpg format.
Math questions:

  1. Is that a normal chain link fence? Why does it look so warped?
  2. Why does the picture take up a bright circular region, with black outside?
  3. Why is the bottom of the circle cut off? (It was like that in the original photograph.)


Elmo. Bigger version, in jpg format.
Math questions:

  1. What shapes are those big round things? Do they all have the same shape and size? How are they arranged?
  2. Why does Elmo have three arms?


Bed and breakfast. Bigger version, in jpg format.
Math questions:

  1. What shapes are the globes on the lamp in the photograph? What shape are they in real life?
  2. How big are those plants in the foreground in real life?

Why does everything look so distorted?

Answers will show up eventually here, or send e-mail to

addington@gallium.csusb.edu
.

The camera.


amera.
Our camera is an imported Venetian biscotti tin (Baicoli). The inside is spray-painted matte black. A biggish hole was drilled in the center of the lid. A square of heavy aluminum foil (from a disposable cookie sheet) with a pinhole in it is taped over the drilled hole, using electrician's tape. The pinhole is the lens of the camera. The shutter is a piece of the foil paper that film comes in. There are pieces of tape on the shutter to hold it up or down, as appropriate.

The film is black-and-white print paper. It is held in place (in principle) by two strips of black cardboard glued to the inside of the camera. Although the lid seemed to fit tightly, it wasn't lightproof (our first pictures were all white). These light leaks are covered by a strip of black felt held on with a strip of elastic. To change the "film", you need either a darkroom or a changing bag. When the film is developed, you get a negative, from which you can make a contact print.

Picture of pinhole camera taking a picture (jpg).
The pinhole picture didn't turn out. I think I put the paper in backwards (easy to do in the dark). The "tripod" is a plastic box; the camera is secured with masking tape and a bungee cord. It is important for the camera to stay still, since exposures are two minutes or more.

are two minutes or more.