Bokeh is usually not associated with pinhole photography. This is because light travels in straight lines and therefore there should not be any apparent blurring with a pinhole that would cause bokeh in the same way that a lens might render it.
There is a good reason that a pinhole is not as sharp as a lensed image: the whole image is made up of nothing but bokeh circles. Normally, the effects of pinhole bokeh are hard to see, because they are usually miniscule details within a pinhole image.
A tiny pinhole creates a very small cone of light, so the image formed is not going to produce a pinpoint accurate rendition. Instead, the image is made up of soft circular projections of all the light points in the scene. Each tiny circular spot is blended into the adjacent circles to create a slightly blurred likeness of the scene being imaged.
The size of the opening or pinhole determines the size of the projected cones, while the distance from the camera will also produce proportionally smaller or larger image circles relative to the size of the opening.
To illustrate that there is plenty of great bokeh concealed in a pinhole image, this image was made using a particularly large opening. The diameter of the opening used to create it is approximately 2mm—the effect it gives is like blowing up a small portion of an image created with a much smaller pinhole.
Focus in Photography is John Neel’s exploration of advanced focus that will greatly enhance your skill as a photographer. These pages will show you everything, from high-end techniques to create infinite focus, through to using it as an artistic tool, directing your viewer’s eye around your photographic composition.