Tried it with a zone plate. Horrible results as the film just isn't optically clear enough. I have some glass plates for lantern slides I mean to try out.

I think the film I used, Arista premium lith, wasn't suitable. Kodak 'line film' would probably have been a better choice.

I think commercial zone plates are made on some sort of lith film - that may be the reason for their overly diffuse imaging.