Pinhole shape has a big influence. You can use that creatively (see Renner's book) or you can go for a laser-cut pinhole to optimize image quality. I can offer a contact at the University of Munich, Germany who can laser-cut pinholes into thin brass plates for you at a reasonable price. he made all of mine.[/QUOTE]

I am "new" to piholes,as I have not done it in several years. And even when I was trying to do it I was nowhere near the leval of accuracy that people on this Forum are about. But it seams to me that one cannot speak of pinhole diameter and ignore thickness of the material used.
One gentleman,on another thread, talks about hammering,filing,over and and over,until microscopic inspection shows perfect roundness and a very thin wall.
Laser drilling will leave a wall the same thickness as the thickness of the original foil.
Regards to all,