Quote Originally Posted by wildbillbugman View Post
My question is: Is not sharpness directly related to the uniformity,as well as the size, of the hole. Would not a laser drilled hole yield a sharper image than a pin prick of the same diameter?
Yes, likely; it's a sure bet just pushing a pin through foil or thin sheet stock will produce curled edges and occasional cracks along the edge. The type of pinholes I have made are not exactly a pin prick. A pin or needle is used to emboss a small "pimple" without actually piercing the metal, then the pimple is sanded with a gentle circular motion, generally with very fine (#400 or #600) wet sandpaper. This can produce a fairly uniform hole with a knife edge, which is also desirable. It also can be done in several iterations, working from each side. The method is described in a number of articles on making pinhole cameras.

I believe larger format cameras tend to produce sharper results also.