if you just want to achieve non-linear falloff (that's apodization) then all you need to do is the graduated-density filter I mentioned, with darker edges and a

if you just want to achieve non-linear falloff (that's apodization) then all you need to do is the graduated-density filter I mentioned, with darker edges and a clear center. In principle you could probably expose a negative or laser-print a transparency to your specifications. (laser-printing a negative for direct contact printing is kind of a fun process in general!) the idea of using a polarizing filter (privacy filter) is kind of an interesting one, can't really picture in my head whether or not that would work. I think the answer might be that yes it would probably change the bokeh, but it might also result in uneven illumination across the image or weird color shifts? it would be neat to see what happens though. possibly also of interest: https://en.wikipedia.org/wiki/Photon_sieve https://en.wikipedia.org/wiki/Photon_sieve