SVG Zoneplate & Megapinhole generator
You can find a small Zoneplate & Megapinhole generator at this address : https://lucassifoni.github.io/zoneplate/
The output has been tested with an adjustable-focus tube on a Canon EOS 550D and works great. Your biggest challenge will be the physical realisation of the pattern. We have had good results with the imagesetting company V-MACH near Lyon, France.
Source code is at https://github.com/lucassifoni/zoneplate . Feel free to fork & adapt to suit your needs.