|MadSci Network: Physics|
Dear Harry, Fisheye lenses, which are different from ordinary wide-angel lenses, work according to the "retrofocus" principle, i.e. by suitable combination of lens elements the distance between the lens and the image plane is made much larger than the focal distance. See the site: http://www.laurin.com/DataCenter/Dictionary/CD/dr/retrlens.htm It's something like looking through binoculars in the "wrong" direction. Best regards Werner Sieber
Try the links in the MadSci Library for more information on Physics.