Quote Originally Posted by wildbillbugman View Post
But it seams to me that one cannot speak of pinhole diameter and ignore thickness of the material used.


I totally agree, I strongly believe (= I have not done any trial or calculation, which is not scientific) the thickness is one of first order parameter.

You can find here a work (sorry in French) made by a gentleman call Claude Boutet. He concludes, what intiutively looks logical, that the thiner the material is the better it is. The only proble that a infitively thin material does not exist. And from what I can see mathematical approach usually assume an infinitively fine material.