----- Original Message ----- From: "karl shah-jenner" <shahjen@xxxxxxxxxxxx> Subject: Re: Digital lens question > > > It might do well to know the Petzval principle. > > http://www.atmsite.org/contrib/Ceragioli/newrefractor/chapters/Chapter%205.h > tml > > worth a read Steve.. > > the fact that the lens elements are set wide does *NOT* negate the fact that > the light is brought to convergence with focussing > > k > > I'm not going to get into a discussion of physics with you Karl. The reason I suggested you look at the Petzval principle and his discoveries/designs for the photographic lens explains just how the photographic lens is NOT like the telescope lens. The original question was 'is there a difference between regular 35mm lenses designed for film and Digital camera lenses. The answer is yes. When I sit with a lens designer, just after his meetings with our NSA (National Security Agency) and listen to detailed explanations about the differences between digital lens design and Petzval film lens light capture, I simply tend to believe him. My answer to the original question was quite accurate. Your research would do well to go to Kodak manufacture via 1-800 424-2424 ext 19 and ask them. "Is there a difference in the lens?" They may well transfer you to the engineer who can clarify that criteria. Meanwhile, I answered the original question and have no desire to further define my answer. S.
