Archived posting to the Leica Users Group, 1999/01/27
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]I have been reading this thread with interest and I would like to pose a question- maybe Erwin might have some info to give insight to the question posed. I switched to plastic spectacle lenses because the refraction I require makes the prescription so heavy in glass, that for years I hated wearing glasses. With the advent of high refraction plastics, I have a very light pair of glasses, and don't often wear my contacts because the specs are so comforatble now. In the same vein, it seems to me that with the malleability of plastic, the lenses using them would be stury yet light. I also realise that aspherical elements, while not necessary, are like the Programmed Array Logic devices in computers. The single PAL can replace many energy consuming chips, with one- and the aspherical element can lessen the element count. So, what is the disadvantage of a lens with fewer elements and air-to-glass surfaces, and lighter? Of course, the plastic spectacles get scratched, and I would assume that in a camera lens, that the plastic elements would be interio, but it seems to me that there would be not real disadvantage. It makes me recall the experience we had at the police department when the detectives were issued Glocks; there was concern over the plastic resin slide. They were afraid the plastic would not stand up, plastic melts, plastic is inferior. Actually, the lead in the cartridges would melt before the plastic, and with impacts tests, the Glock , singularly, survived a multistory fall from a building, where are the more traditionally made weapons didn't. So, what's wrong with plastics? Dan