eSPHOTOS -- Some photographers consider Rayleigh's formula to yield too large a pinhole. Rayleigh based his formula on the scientific principles of 120 years ago rather than on the photographic experiences of today. I use Pinhole Designer with a user constant of 1.5 instead of the 1.9 Lord Rayleigh constant. This seems to give the best sharpness in the center of the image, although sharpness in pinhole photography is more subjective than objective. Some of us expend more energy in squabbling over optimum pinhole diameter than in taking photographs. It does provoke us into learning more about this suprisingly complex subject.