Quote Originally Posted by Mike Walker View Post
Hi Wild Bill
Mike Walker here I make the Harman Titan pinhole cameras, acid etched holes are superior to laser holes, and if done the right way they very very round, I am going to upset some here, put round does not matter that much, it is more the sharpness of the inside edge of the hole.
I can back this up, as Schneider once had a play with this, and by taking 3 scalpel blades interlocking they and blacking with candle smoke made what they said, was as sharp a pinhole as it was possible to make.
Hope this helps.
Sharpness in pinhole images is limited by diffraction at the edges of the pinhole. The triangular pinhole has greater edge length in relation to the opening area than does a circular pinhole. However, there is one advantage to a triangular pinhole; by moving only one blade the aperture can be varied. With more care, a four-sided variable pinhole can also be constructed.