Pinhole camera

From Math2033

Members

Nathan Smith

Meredith Eades

Weston Chapman

What is a pinhole camera?

A pinhole camera is a small, light proof box with a single pinhole sized opening in its side that acts as a lens. Pinhole cameras can be made out of many different things. Soda cans, oatmeal containers, and match boxes can all serve as the housing of a pinhole camera. The function of a pinhole camera is relatively simple, light passes through the opening, also called an aperture, and an inverted image is projected and captured on film inside the camera. The size of the aperture and film exposure time are the two most important factors of taking pictures using a pinhole camera.

The Aperture

The smaller the aperture the sharper photographs will be. However, the aperture can be made too small, this will cause diffraction effects and the image will be blurred. The formula d=1.9√fλ (diameter equals 1.9 multiplied by the square root of the focal length times the wave length) was developed by the physicist John William Strutt to find the ideal sized aperture. This formula is primarily used by professional photographers and artists, as for the hobbyist a household safety pin creates a perfectly usable sized aperture. The aperture should be as round as possible to ensure equal light distribution to the film. A hole punched through a thin piece of metal or cardboard will retain the circular shape of the pin and thus make ideal materials for creating an aperture.

Film Exposure

Film exposure time gives pinhole camera users the chance to get creative. A manual shutter is typically installed in pinhole cameras as exposure time can vary any where from two seconds to several hours. In order to get a clear picture the camera must remain perfectly still the entire time the shutter is open. If the camera moves while the shutter is open the image will blur and run together. There should be plenty of light when taking pictures, if light conditions are poor the photo will appear grainy and dark. These steps must be followed to get sharp, life like photos, however manipulation of these rules can be used artistically to create visually striking images.

The Process

First, we gathered our materials: 1 matchbox, 1 roll of 35mm film, 1 roll of black tape. Then (in a completely dark room), we put the roll of film through the box. Next, we used the black tape to wrap around the matchbox and seal up every possible gap in the matchbox where light could get in. Then, we poked a hole in the top of the matchbox and put another strip of black tape over the hole. Next, we went outside and found a large tree that we thought would be perfect for our pinhole camera picture. We removed the strip of tape above the hole for a split-second so that the light and the image could be captured on the strip of film, then we quickly covered the hole back up.

We thought that it would be a simple process finding someone to develop our strip of film, but it turns out that none of the film developers and processors in Northwest Arkansas develop single strips of film in a black room anymore, they only work with full strips of film. We tried contacting the photography department at the University of Arkansas but no one there could develop our picture either. So, since we constructed our camera and captured our pictures but could not find someone to develop it, we have provided examples below of others' successful attempts at building a fully-functioning pinhole camera.