Archived posting to the Leica Users Group, 2010/05/27
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Thanks, Frank, for clarifying how you perform the test. I found that my M3 and M6's RF alignments are very close to each other, that I cannot tell a difference. So the negatives from the M3 look like the negatives from the M6, with the differences being down to what lenses are being used. As to the lenses, I found that my 50mm Summicron is spot on. The focal plane is where I focused with the RF, with the out of focus areas properly in front of and behind that plane. Nice to know. The Tele-Elmarit is front focussing, but not as badly as my Nokton. My Tele-Elmar's front focus is such that the point where I focus with the RF is just in or just outside of (depending on distance from lens) the rear fringe of acceptable sharpness. The Nokton, at all three distances, was not focussing where I focussed the RF. It was front focussing far too much, such that at the farthest distance in my test (340 cm) the lens focusses about half a meter in front of where I set the RF. At all distances, with my Nokton wide open, the intended plane of focus was significantly behind where the lens actually focussed. The question is what to do next. Today I sent my two Leica lenses to Solms, because Andrea Frankl suggested that I send them there to make sure they work well with my M8. I told her I noticed discrepancies between the M8 and the M3 & M6 regarding front/back focussing. When I used the Summicron on the M8, I had to unscrew the front part from the rear part of the lens and reverse the shim. Because one rim of the shim is flat, and the other rim comes to a point, this made the lens ever so slightly longer. I then screwed the front back on, and finally unscrewed it slightly, so that is held but was not completely tight, and made the lens slightly longer yet again. Then I found the M8 could focus the 'Cron. I am confident that when the M8 and Leica lenses are returned to me, they will work together as well as possible. But I am slightly worried that when they come back, the 'Cron will no longer work well with the film cameras, and the Tele-Elmarit might be even more mis- aligned. On the other hand, maybe all the members of my little Leica family will play very nicely together and live happily ever after. The thing is, if they don't all play nicely when reunited, I'm not sure what to do, short of then sending everything back to Solms. Anyway, I've pretty much decided to think about properly when my parcel arrives from Solms. As for the Nokton, it seems it is badly out of focus on my film cameras, although it was focussing better on my M8. Again, I probably won't decide what to do about that until my M8 and Leica lenses come back home. In a nutshell, I found that my film cameras were probably not out of RF alignment, and that my Nokton lens was to blame for recent unintended soft-focus photographs, due to severe front-focussing. I also found my Tele-Elmarit was front-focussing, not as badly as as the Nokton, but enough for me to want to get it seen to by a Leica technician. I was nicely surprised to find the Summicron was spot-on, despite the fact that it needed a troublesome workaround to focus well with the M8. Thanks for helping me think about this, Frank. It was confusing me for a while. All the best, Peter