Equation for determining the exposure time of pinhole cameras
http://www.pinhole.cz/en/pinholecameras/exposure_01.html http://www.mrpinhole.com/exposure.php https://en.wikipedia.org/wiki/Pinhole_camera Selection of pinhole size [ edit ] Up to a certain point, the smaller the hole, the sharper the image, but the dimmer the projected image. Optimally, the size of the aperture should be 1/100 or less of the distance between it and the projected image. Within limits, a smaller pinhole (with a thinner surface that the hole goes through) will result in sharper image resolution because the projected circle of confusion at the image plane is practically the same size as the pinhole. An extremely small hole, however, can produce significant diffraction effects and a less clear image due to the wave properties of light. [9] Additionally, vignetting occurs as the diameter of the hole approaches the thickness of the material in which it is punched, because the sides of the hole obstruct the ligh...