One interesting diffraction phenomenon occurs when light passes through a pinhole in a board. Light passing directly through the pinhole would seem to create a spotlight. But this is just an illusion. You actually get a circle pattern with ripples of brightness and darkness. The sharpest bright spot is at the center, and ripples expand further out around the center. We call this the diffraction image.

This rippling is quantified in what we call a two-dimensional Fourier transformation. Some scientists have proposed the concept of an "optical computer," which would use the diffraction of light to make calculations with greater speed.