What is a zone plate?

"A zone plate is a way of focusing light, like a lens, but using fresnel diffraction instead of refraction. This is cool from a theoretical point of view, because it demonstrates the wave nature of light. And it's cool from a photography point of view, because the images produced have a unique glow, with an impressionistic almost-painted look." Read more here.

These images were created by attaching a zone plate body cap to a traditional DSLR camera.