lawman Posted May 7, 2016 Share #1 Posted May 7, 2016 Advertisement (gone after registration) I have obtained a late manufacture 75 Lux in lovely condition. It was supposedly 6 bit coded and cla'd by Leica. At 2 meters at 1.4 it is backfocussing 1-2". Is this something I have to live with, with this lens or should it go back to mother for adjustment? My m240 focuses right on with most of my other lenses and I use a 1.4 magnifier. Thanks for opinions. Quote Link to post Share on other sites More sharing options...
Advertisement Posted May 7, 2016 Posted May 7, 2016 Hi lawman, Take a look here 75 summilux back focus question. I'm sure you'll find what you were looking for!
JeffWright Posted May 7, 2016 Share #2 Posted May 7, 2016 I have obtained a late manufacture 75 Lux in lovely condition. It was supposedly 6 bit coded and cla'd by Leica. At 2 meters at 1.4 it is backfocussing 1-2". Is this something I have to live with, with this lens or should it go back to mother for adjustment? My m240 focuses right on with most of my other lenses and I use a 1.4 magnifier. Thanks for opinions. I had the same problem with my 75 'lux, including the 6-bit coding and CLA by Leica. For a couple of years I attributed my hit or miss focussing with the lens at close focus to my error, but sent it to DAG this winter for focus adjustment, it's now spot on. 1 Quote Link to post Share on other sites More sharing options...
pico Posted May 7, 2016 Share #3 Posted May 7, 2016 Not true of my first generation 75mm Summilux. Pay Solms or adapt. Quote Link to post Share on other sites More sharing options...
JWW Posted May 7, 2016 Share #4 Posted May 7, 2016 When I first obtained my 75mm Summilux in the M8 days, it was off focus. I sent it in to DAG and it's been spot on with subsequent M9 and M240 cameras. Quote Link to post Share on other sites More sharing options...
pico Posted May 7, 2016 Share #5 Posted May 7, 2016 (edited) When I first obtained my 75mm Summilux in the M8 days, it was off focus. I sent it in to DAG and it's been spot on with subsequent M9 and M240 cameras. So what did DAG do to correct it? That is what I want to know. Was the helix cut incorrectly (unlikely) or was the thrust surface incorrect? That is the most important issue! Rick, pay attention. . Edited May 7, 2016 by pico Quote Link to post Share on other sites More sharing options...
JWW Posted May 7, 2016 Share #6 Posted May 7, 2016 Sorry, I don't have any details on how or what DAG did to adjust the lens. Quote Link to post Share on other sites More sharing options...
jaapv Posted May 8, 2016 Share #7 Posted May 8, 2016 Advertisement (gone after registration) He probably replaced the shims. Quote Link to post Share on other sites More sharing options...
JeffWright Posted May 8, 2016 Share #8 Posted May 8, 2016 Not true of my first generation 75mm Summilux. Pay Solms or adapt. Sadly, I paid Leica New Jersey, not Solms directly. I suspect that's the problem. Quote Link to post Share on other sites More sharing options...
darylgo Posted May 9, 2016 Share #9 Posted May 9, 2016 He probably replaced the shims. Where are the shims placed? Quote Link to post Share on other sites More sharing options...
pop Posted May 9, 2016 Share #10 Posted May 9, 2016 So what did DAG do to correct it? That is what I want to know. Was the helix cut incorrectly (unlikely) or was the thrust surface incorrect? That is the most important issue! .... Im not familiar with the 75mm Summilux, but I have sent in a 90mm Elmarit-M to Leica (Switzerland) for coding. When they sent it back, they stated that they had adjusted focus for infinity. I did not like the new behaviour and re-sent it, asking to improve focus for the close range. This they did and it was off at infinity. They said they couldn't adjust the lens for the whole range as they had run out of some parts. This would suggest that the helix was off; I wonder whether different copies of that model varied by such an amount that they needed different helices. Quote Link to post Share on other sites More sharing options...
jaapv Posted May 9, 2016 Share #11 Posted May 9, 2016 A really good independent repairer could file the helix, maybe.BTW. the placement of the shims depends on the lens design. Sometimes between the optical cell and the barrel. I once had a 21/2;.8 ZM that shifted an element and Will told me each individual eement was shimmed. FWIW. Quote Link to post Share on other sites More sharing options...
pop Posted May 9, 2016 Share #12 Posted May 9, 2016 I don't think filing would work. You'd have to turn a helix with a different steepness (if that's the term). I don't see how filing can turn a too steep helix into a flatter one, for instance. Quote Link to post Share on other sites More sharing options...
byroncheung Posted May 24, 2016 Share #13 Posted May 24, 2016 He probably replaced the shims. I sent my copy to DAG couple of years ago to calibrate it he did have to shim it. Quote Link to post Share on other sites More sharing options...
pico Posted May 24, 2016 Share #14 Posted May 24, 2016 (edited) We had a member who used micro-thin adhesive copper tape to shim the push cam of a lens. Perhaps a search is called for. EDIT: Here is one of his mentions. Edited May 24, 2016 by pico Quote Link to post Share on other sites More sharing options...
Manoleica Posted May 24, 2016 Share #15 Posted May 24, 2016 A ? comes to mind:- If a lens back or front focuses does using Hyperfocal setting cover the issue? - Quote Link to post Share on other sites More sharing options...
NB23 Posted May 26, 2016 Share #16 Posted May 26, 2016 A ? comes to mind:- If a lens back or front focuses does using Hyperfocal setting cover the issue? - The whole range shifts. Quote Link to post Share on other sites More sharing options...
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