Zone plate photography is similar to pinhole photography, in that the “lens” is a diffractive element. Zone plates images have a different look than pinhole images. Zone plates potentially have higher resolution.

Construction of a zone plate is trickier, in that you can’t practically make a pinhole by manual means. A pinhole can be drilled, but a zone plate has too many precise features.

Instead, a zone plate is reproduced by photographic means. A master is printed as a negative image, shot at a specific magnification ratio, processed and mounted, usually into a body cap. You can also send a zone plate image to an image setter service and they will burn it to film for you.

Zone plate This is the master image I used as the basis of my zone plate. I won’t go into specific details of how to make a zone plate, they are easily found at Mr. Pinhole. Additionally, there is a postscript pinhole generator at whizkidtech.

The whizkidtech files, once imported into illustrator, need some fixing, but the align tool is really helpful for getting things concentric.

My process was to shoot the pinhole master with my Bronica GS-1 50mm on Rollei Ortho 25. I shot several exposures form normal to +/- 2 stops over/under and picked the best. I processed in D76 stock solution because that is what they have at the lab at school. I didn’t get exceptionally high density of my negatives, so I may have to use the recommended developer and shoot again.

Update: I have built a sheet of pinholes that I am going to have photoset at an image setter. Imagesetting service bureaus were easy to fine 20 years ago, but with direct to plate printing being common, they are harder to find. I am going to use Imagesetting Bureau.

I am running 2 sets of zone plates. A series with 8 rings, in the following focal lengths 18mm, 25mm, 50mm, 75mm as well as a series of focal lengths 18mm, 25mm, 50mm, 75mm  @ ~f31.  Additionally I am running a 3rd zone plate with a focal length of 20mm and @f12.

UPDATE The image set zone pates came out terrible… BOught some high contrast developer and will try my own zone plates again…

Here are some exceedingly processed shots. All shot at ISO 12800 on my Fujufilm      X-T2. The resultant graininess is something I enjoy, and can process as I like.

Koitato

Worth noting, you can shoot other things than koi with a zone plate, but I have easy access to a koi pond while I do my experimentation.

Here is a good page that describes technically what a zone plate is: zone plate maths