Pinhole cameras are used for fun, for art, or for science. Pinhole cameras are small or large, improvised or designed with great care. Cameras have been made of seashells, of salt shakers and watermelons. Cameras have been cast in plaster like a facemask, constructed from beautiful hardwoods, built of metal and fitted with bellows. Station wagons have been used as pinhole cameras, as have rooms in large buildings.
Some photographers delight in making cameras out of surprising objects.
But most pinholers start out with a simple cardboard box or a small circular metal or cardboard container. What counts in the final analysis are the images produced by the camera. Extraordinary images can be made with a very simple cardboard or can camera. Some images could not have been made with a lens. The pinhole itself, the most important part of the camera, is basically a sophisticated lightleak.