Construction of the Pinhole Camera

The camera is built almost entirely out of corrugated cardboard, poster board, and tape. The main box shape is made of a single large sheet of cardboard, cut halfway through at the joints, so that the pieces fold together to form a box. I sealed all the joints with glued strips of dark paper to keep light from getting through. I spray-painted the inside with black paint to reduce internal reflection of light.

The "pentaprism housing" (pyramid shape on top of the camera) serves as a viewfinder for framing the picture. Of course, there is no prism inside. There is just a small hole in back and a larger hole in front for framing the scene being photographed.

I used masking tape to seal the outside edges of the camera where there were gaps in the partially-cut, folded cardboard. After a year or so, the tape started coming apart. I should have used glued strips of paper cut from a brown bag instead. That would have been more durable and would have looked better, too, because the paper has a smoother, more even texture when painted.

camera back open without film

To make the door for installing the film, I made three full cuts and one partial cut through the cardboard, thus forming a tight-fitting, rectangular hinged flap. To prevent light from leaking through the edges, I glued on a slightly larger, overlapping rectangle of poster board on the outside surface of the flap. I also glued on matching narrow strips of poster board onto the back of the camera along edges. On the inside of the camera, I glued strips of poster board overhanging the opening. I also glued matching narrow strips of poster board on the inside of the door. The door edges are probably light-tight, even in bright sunlight.

A metal film holder is glued to the inside of the door. I bought a box of these Kodak metal film holders at a yard sale. They are designed to allow 4 X 5 sheet film to be installed into a photographic glass plate holder. To load the camera, I slipped a sheet of film into the holder as shown below. Of course, this had to be done in the darkroom.

inserting the 4 X 5
                film4 X 5
                film inserted into holder

After closing the door, I locked it in place with the cardboard slide strip shown below.

locking slide strip

I made a tightly-fitting "camera case" out of corrugated cardboard. The camera slips into the case and is held by friction. By this time I realized the value of using paper and glue rather than masking tape to seal the joints. I never got around to painting the case.

camera and case

On the bottom of the case is a long rectangular piece of circuit board with a drilled 1/4-inch hole. The hole is located directly under the center of gravity of the camera. Behind the hole, I glued a hex nut with 1/4-inch threads. This allows the camera to be mounted on any standard tripod. This feature is important because the camera must be held very still during the exposure.

camera case, bottom view

Next: Using the Camera

©2005 Gray Chang