I have to admit prior to the Delta 3200 thread today I haven't seen any practical examples of zone plate photography.

I'm intrigued, particularly for (very) soft portraits. In SLRs I primarily use Pentax K-mount, but also have an M42 adapter. I also have an older Mamiya 645 that hasn't seen much use (by me, anyway).

I've been searching around, but I don't see many options for pre-made zone plate body caps or longer focal lengths for these systems. I was able to find one for M42 here (http://www.atnimage.com/products.html), and a Finney 150mm combination pinhole/zoneplate arrangement in K-mount here (http://www.calumetphoto.com/item/PY2127/) (which is a bit too expensive for me just as an experiment), and I don't see any for the M645.

Are there other sources I'm missing?

Pinhole Resource sells zone plates in 10 focal lengths. If you want something longer than a body cap, you could use extension tubes and a zone plate for the film-to-flange + extension tube distance if you can find a combination that suits you. You could mount a zone plate in your own body cap for that application.

http://www.pinholeresource.com/shop/shop?page=shop.browse&category_id=17

Lee