Archived posting to the Leica Users Group, 1998/06/23
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]People don't realize that scratches or other glitches on a lens element interrupt such a minuscule number of the light rays that pass through a lens, to make a photograph, that unless the affected area is large, there is no way to tell that the photograph was taken by a damaged lens. Perhaps with optical instruments, but certainly not the human eye looking at a slide or print. A fine layer of almost invisible dust, scum, oil, (a dirty lens) will cause far more problems than a scratch, or as Chris said, a hole. It's the number of rays interrupted and re-distributed (flared) that cause the problem. A dirty lens affects all the rays, not just a minuscule number like a scratch or pit. Now for the real controversy... This is even more important on a filter because a filter does not have the very expensive, highly refined, extra hard coating that a modern Leica lens has. Flare caused by grime on a filter is much worse than flare caused by grime on a lens front element alone. If nothing else, it's additive. And don't forget, even Leica says that filters can cause flare where a bare front element won't. Keep those lenses and filters clean, and don't sweat the minor glitches. Every Leica lens that comes into Ernst Hartmann's (Service Manager at Leica) hands at a Leica "clean & check" gets a hard rubbing with a chamois. It leaves his hands clean. If you look at the chamois at the end of the day, it's ugly! If not already done, someone should buy that APO 180, advertised on the LUG, for $750. A steal! Jim At 04:31 PM 6/23/98 +0200, you wrote: >At 06:50 22.06.98 +0000, you wrote: >>I recently bought a 35 Summilux with a few light front element scratches >>but the rear element is good. ... > >Yesterday I got my prints back. The pictures were made on Sunday during >mountain trip. I have used R 50/2 Summicron with a painful hole punched on >the front element, the rear element being cristall clear. I was afraid >about the results, but I am astonished. The pictures look great. The >sharpness is like a razor. The colour rendition perfect. And the lens is >for 1/3 price to take!!! Don't tell anyone :) > >Chris >