Film for making zoneplate

[crispinuk]

I'm thinking about making a zoneplate for this year's World Pinhole Day. I have plenty of info on making the zoneplate image and photgraphing it, but I'm not too sure on the film to use (to make the zoneplate with). Kodalith is mentioned but I don't know if it's still available anywhere or if ever in 35mm.
Ideally it needs to be 35mm so that I can make lots of bracketed shots to ensure I get at least one good frame to use, using a 4x5 sheet to make a 5mm image seems a bit wasteful.
Retrophotographic(.com) show an Agfa Copex/Spur Nanospeed film developer pack that looks promising. The Copex is described as microfilm so does it a have a transparent base and have high contrast ? Is the fact that the nanospeed developer makes it behave like a pictorial film not relevant because I'm photgraphing a purely black and white (not continuous tone) target, or would developing it to give very high contrast 'transparent and black' make a better zoneplate ?
If anyone can understand what I'm waffling on about and can make any suggestions for films and the best way to use/develop them for this purpose I'd be very grateful.

Thanks
Crispin

 

[sanking]

I'm thinking about making a zoneplate for this year's World Pinhole Day. I have plenty of info on making the zoneplate image and photgraphing it, but I'm not too sure on the film to use (to make the zoneplate with). Kodalith is mentioned but I don't know if it's still available anywhere or if ever in 35mm.
Ideally it needs to be 35mm so that I can make lots of bracketed shots to ensure I get at least one good frame to use, using a 4x5 sheet to make a 5mm image seems a bit wasteful.
Retrophotographic(.com) show an Agfa Copex/Spur Nanospeed film developer pack that looks promising. The Copex is described as microfilm so does it a have a transparent base and have high contrast ? Is the fact that the nanospeed developer makes it behave like a pictorial film not relevant because I'm photgraphing a purely black and white (not continuous tone) target, or would developing it to give very high contrast 'transparent and black' make a better zoneplate ?
If anyone can understand what I'm waffling on about and can make any suggestions for films and the best way to use/develop them for this purpose I'd be very grateful.

Thanks
Crispin

My friend Sam Wang makes zone plate lenses with Kodalith film. I don't believe Kodalith is made anymore but you can apparently still find it on ebay, at least from time to time. There may or may not be be other alternatives in 35mm.

Sandy King