Lindolfi Posted January 10, 2011 Share #41 Posted January 10, 2011 Advertisement (gone after registration) Thanks crfcuibap, but that is a completely different adjustment. When all your lenses focus fine out of the box and one is backfocussing, it usually is the lens that has a problem. When you would adjust in the camera, all your other lenses do not focus well anymore. Therefore I posted my tip here how to adjust the only one with backfocus, in my case the Nokton 1.1 Quote Link to post Share on other sites More sharing options...
Advertisement Posted January 10, 2011 Posted January 10, 2011 Hi Lindolfi, Take a look here Nokton 50mm f/1.1 Backfocus. I'm sure you'll find what you were looking for!
jaapv Posted January 10, 2011 Share #42 Posted January 10, 2011 Well, I'm not convinced I would take a hammer to a lens; it cannot do the threads of the adjusting mechanism much good... Quote Link to post Share on other sites More sharing options...
Lindolfi Posted January 10, 2011 Share #43 Posted January 10, 2011 (edited) If the cam is carried well during tapping, no forces or torques are applied to any threads. Lens focusses smooth and accurate and is usable now. Understandable that you are not convinced, you have not seen and felt the lens or tried it yourself. I'm reporting here in case someone has the dexterity to use it. Sharing is an important function of a forum like this. Edited January 10, 2011 by Lindolfi Quote Link to post Share on other sites More sharing options...
Bo_Lorentzen Posted January 10, 2011 Share #44 Posted January 10, 2011 My lens had the same issue with slight back focus, problem solved in about 10 seconds by applying a coat of my girlfriends back fingernail polish on the cam, wait 30 minutes to cure with a nice shine, then test on camera, apply additional coats as required. I recommend letting it cure for at least a day before regular use so the polish can be as hard as possible, if not cured the focusing cam will simply leave a dent in the polish. I do understand the hammer method, still the fingernail polish seems a bit less forcefull to me and works very well. . 1 Quote Link to post Share on other sites More sharing options...
Lindolfi Posted January 11, 2011 Share #45 Posted January 11, 2011 Good suggestion as a temporary measure Bo_Lorentzen. With the tapping method, you have the same wear resistance as the original cam. Quote Link to post Share on other sites More sharing options...
richfx Posted February 3, 2011 Share #46 Posted February 3, 2011 Just wanted to follow up. I ended up ordering a new 50mm f/1.1 Nokton from the second batch, which supposedly corrected the back-focus issue on the digital M's. All I can say is that the lens I received is spot-on at f/1.1 on my M8.2. Awesome lens! Cheers. -Norm dNorm - can you provide the serial number of your new / replacement Nokton 50mm 1.1 (and that of the original, if you have it)? I just ordered a new Nokton 50mm 1.1 and would love to know if indeed a later batch (that hopefully includes mine) has fixed or addressed the focus shift problems reported. Rich Quote Link to post Share on other sites More sharing options...
PCPix Posted March 12, 2018 Share #47 Posted March 12, 2018 Advertisement (gone after registration) Bought an unused Nokton 50/1.1 for 600 Euro a few days ago and tested it beforehand. Found backfocus with a constant amount of turn of the focus ring to focus correctly, so I trusted I would be able to correct that. As suggested earlier in this thread that the cam could be polished is wrong when the lens backfocusses! The cam is too short, not too long. So, in very small steps I compressed the cam of the lens by tapping on it with a small hammer, using a flat headed pin (diameter 3 mm) exactly in the middle where it (when mounted) rests agains the rangefinder wheel of the camera. The other side of the cam was supported well with a steel flat object. This compression makes the cam a bit longer (just a few hundredth of a mm) and now the lens focusses exact throughout the range of focussing, from 1 meter to infinity. It took me about half an hour to correct it. It is not necessary to take the lens apart. There is enough room for the pin to reach the cam from the inside when the lens is set to infinity. The outside of the cam is supported by the steel flat object. the lens is supported with a bean bag for instance. So perhaps worthwhile for those who feel they have an overpriced paperweight. But beware: you need only light hammer taps to get the effect needed. If you did too much, you can file it off with a very fine diamond-powdered file, but when you take your time, that is not needed. Tap not quite at the edge of the cam, you want the edge to remain smooth, just about 2 or 3 mm away from the edge with the pin lightly resting on it. Here an example of how well it focusses, taken at f/1.1, focussed on the lips (square crop at full height taken with the M9, no post-processing): click (I dremel coded the lens as a Noctilux 1.0) The lens certainly is worth being corrected, because it is very sharp indeed. Ok - I know this is a very old post, however I have just made this adjustment using a 25mm socket as the 'anvil' (which exactly matched the radius of the focus cam) and a wide blade screwdriver as the 'punch' and with the lens suitably supported so all impact goes only into the focus cam/tab - with some very gentle tapping it brought the back focus forward to precise focus on my M10. Very happy with the results coming off the lens now and absolutely bang on all the way through the focus range. BTW this lens was my only lens that was off, Summilux 35mm FLE, Summicron 75mm, Elamrit 90mm all spot on, so no suspicion of the body being out. Quote Link to post Share on other sites More sharing options...
Sandokan Posted March 17, 2018 Share #48 Posted March 17, 2018 Hello folks. I just bought a used Nokton 50/1.1. The original owner had it only for about a month (bought it for his dad), but as it turned out it his father couldn't use it. Well, it has backfocus, I tested it at f/1.1 - f/4 on a tripod with an E-P1 pointed through the viewfinder and at 10x magnified live view just to ensure that my eyes were not the culprit of mis-focusing. Has anyone else experienced backfocusing with their 50/1.1 Nokton? I don't believe it to be a focus issue on my new M8.2 (about 3 months old). My M8.2 focuses perfectly with all my Summicrons and focuses fine with my 40/1.4 Nokton. So, at this point, I'm excluding the possibility of it being a body issue, unless someone with experience can convince me otherwise. I do realize that f/1.1 puts a strain on the focusing system of any camera but I am relatively confident that my M8.2 is fine - there is such an obvious difference between my Nokton 40/1.4 and 50/1.1, the latter showing obvious backfocus, the former looking sharp. Comments and/or experiences appreciated. -Norm HI Norm, Trying to understand your testing. E-P1 has an electronic viewfinder and focus is through the lens so should be 100% accurate. You should never see backfocus through it. I had focussing issues with some lenses on my M8 and the test was to place an engraved ruler at a 45 degree vertical angle and focus on the 15cm mark. The photo then showed that it was the 14cm mark that was perfectly in focus. The camera and lenses were sent off for re-calibration. Sorry I cannot find the photos of my testing. When I had a similar problem with the M, it was simpler; on a tripod, I focused with the optical viewfinder and then put my eye to the EVF and sure enough, subject was out of focus. What do you mean by "backfocus"? In my case above, it was easy to work around as it was possible to focus and just move head and camera by 0.7cm. This can be done when just a single lens has a problem. Test it to work out how far you have to move your head at 0.7m, 1m, 1.5m and 2m. Above 2m I did not have any issues. Quote Link to post Share on other sites More sharing options...
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