Zone plate photography is a close cousin of pinhole photography. Both use a tiny aperture instead of a lens. But in zone plate photography, the aperture is covered with a small piece of film onto which the following is printed:
"The basic principle for the zone plate is simple but fascinating. Light travels in a straight line; that is the reason pinholes work as they do. However, light also bends when it travels past an edge. This is called diffraction. In simple terms, when the diffraction of properly spaced concentric rings is added to a pinhole, it has the cumulative effect of a focusing lens. And since light also travels straight through the same concentric rings, it yields halos around bright objects."
The images on this Web site were made with a converted Lubitel 6x6 camera.