Thank you for your detailed analysis of hole diameter under ambient conditions. It provides a good rationale for using the larger hole sizes that are found in practice.
I speculate that decisions on hole size for churches and other buildings were largely based upon aesthetic considerations. The image had to be easily visible to the public with the maximum interior illumination. This is the case that you analyze.
If it were desired (for scientific purposes) to most accurately determine the position of the image (which it apparently was not), most of the ambient light could be blocked by surrounding the image with a screen. This would permit use of a smaller aperture such as the aperture that you calculate for pinhole cameras.
Gordon Gordon Uber [EMAIL PROTECTED] San Diego, California USA Webmaster: Clocks and Time: http://www.ubr.com/clocks -
