I made a couple of wooden pinhole cameras, based on Zero Image design, and used a laser-drilled (EMS) pinhole, purchased from USA. FL is 30mm, which is about right according to Pinhole Designer software (link in one of the previus posts), with the constant of 1.5 (instead of the default 1.9).
I'm pretty happy with the results: one camera is 6x6 format, and the bigger one is a combo 6x6 - 6x9 camera, and that one uses the same FL and pinhole size (0.2 mm, i.e. 200 microns and 30mm focal length).
Attached are a few results.