Martin, The reference you provided was written by you on another forum. I don't consider this to be a "reference". Can you provide a scientific source to back up your claim (that the same thickness of silver is a better than lead in protecting film from of x-rays)?(posted 8380 days ago)I don't think that the primary concern is about a single roll of film left in a camera, rather it is to protect MULTIPLE rolls of unexposed and exposed film passing through airport x-ray machines. Therefore the composition of the camera is probably not relevant.
Lead has a density of 11.35 g/cm3, and silver has a density of 10.5 g/cm3. I would assume that this has something to do with the ability to shield from x-rays (although since I am not a scientist, I certainly could be mistaken). The medical and dental communities seem to use lead shields to protect patients and medical personnel from unwanted x-ray exposure. Here is a description of lead (Pb) that I found at the Los Alamos National Laboratory periodic table web site: "The metal is very effective as a sound absorber, is used as a radiation shield around X-ray equipment and nuclear reactors..." The description of silver (Ag) does not mention x-ray shielding. http://pearl1.lanl.gov/periodic/