My 4x5 pinhole parameters:
Pinhole to film distance ( "focal length"): 2.44 inches (62 mm)
Exposure Mask Area: 3.9 x 4.75 inches (100 x 120 mm) Diagonal: 6.15 inches (156 mm)
Diagonal Field of View: 103º
Pinhole diameter: 0.012 inches (0.30 mm); about f/210
Pinhole Constant: 1.65
f/22 Exp Multiplier: 88
Weight: 550g (~1.22 lb) with filmholder
If the "coverage" dimension you state is coming from Mr Pinhole, I think it's rather pessimistic but he doesn't actually describe the criteria. I recall it told me the numbers above were good for 4+ inches, vs the 6.15 I'm using. Yes, there is some fall-off away from the center but it's not that awful!
(Backing up from that link will get you to all my pinhole stuff to date, such as it is. )
Last edited by DWThomas; 07-09-2013 at 12:23 AM. Click to view previous post history.