I have been working on a project for quite some time that involves the use of pinhole sieve, and to the left is an example image. This work is recent to the point that I have yet to give it a title. The results have made my other pinhole work appear to be sharp by comparison. The interesting thing about exposure through a pinhole sieve is that specular elements sometimes appear in places where they do not belong. This has been gaining interest with me.
When I try to explain a pinhole sieve, I seldom think that I have gotten the point across, so to the right is an example of one. Of course, a real pinhole sieve will be considerably smaller, but the idea is that the pinhole is surrounded by progressively smaller pinholes. This results in an increase of exposure speed and a lessening of the definition of the subject matter.
I believe that the results are similar to zone plate photography, and will be running some tests at a later time to visually see the difference.