atatexan Posted February 16, 2015 Share #1 Posted February 16, 2015 Advertisement (gone after registration) Having a strange (perhaps not) problem with focus. I bought a used Tele-Elmarit that was a bit rough in terms of the bayonet mount. Focus was off by 18 inches. Returned the lens to the vendor and bought a very nice Summicron F2 90mm - and have the same problem. The odd thing is I have no such problem with a 28mm Elmarit that is 6-bit coded. Very frustrated at this point. What could be causing this focus proble??? I took a photo of a crystal candle stick that was "in focus" according to the view finder. Also took the camera to Mass shooting shot at infinity. Both sets are very blurry. Link to post Share on other sites More sharing options...
Advertisement Posted February 16, 2015 Posted February 16, 2015 Hi atatexan, Take a look here M8 interface with 90mm Summicron and Tele-Elmarit. I'm sure you'll find what you were looking for!
luigi bertolotti Posted February 16, 2015 Share #2 Posted February 16, 2015 The 6 bit coding doesn't enter anyway in your problem : but if your only other lens is a 28, keep in mind that is a focal in which depth of focus is significant (expecially if you shot not wide open) and inconsistency in focusing can be unappreciable: can be that the problem is in the rangefinder adjustment of your camera, which can be easily fixed by a lab : but, better to take some controlled test (tripod etc.) to identify better the problem (first of all at infinity, the with a focus chart at smaller distances). Link to post Share on other sites More sharing options...
atatexan Posted February 16, 2015 Author Share #3 Posted February 16, 2015 I switched off the LENS DETECTION in the M8 menu. Took the same candle stick photo which came out very sharp. It seems 6-bit makes a difference: a non-6-bit lens with LENS DETECTION "on" does not focus properly. Thank you for your prompt suggestion. Link to post Share on other sites More sharing options...
Lenshacker Posted February 16, 2015 Share #4 Posted February 16, 2015 Try a shot of a ruler, at minimum focus and a bit farther out. Mark the spot that you focus on, or use a flashlight to illuminate the midpoint of the ruler for easy recognition. Try to determine if the lenses are front-focusing or back-focusing. The 6-bit coding only affects vignetting of the sensor. It is completely independent of the focus mechanism. Link to post Share on other sites More sharing options...
jaapv Posted February 17, 2015 Share #5 Posted February 17, 2015 I switched off the LENS DETECTION in the M8 menu. Took the same candle stick photo which came out very sharp. It seems 6-bit makes a difference: a non-6-bit lens with LENS DETECTION "on" does not focus properly. Thank you for your prompt suggestion. I bet you moved the camera when switching off lens detection. Focusing has no connection whatever to the electronic part of the camera. Link to post Share on other sites More sharing options...
jip Posted February 17, 2015 Share #6 Posted February 17, 2015 6-Bit does NOT affect focus not even a little. Focussing a Leica M digital or analog is completely mechanical. Link to post Share on other sites More sharing options...
atatexan Posted February 17, 2015 Author Share #7 Posted February 17, 2015 Advertisement (gone after registration) I put the camera on a little Leitz tripod which may have helped. Link to post Share on other sites More sharing options...
atatexan Posted February 26, 2015 Author Share #8 Posted February 26, 2015 The upshot of this issue was conclusively proven to be improperly adjusted focussing cam. Using a rule two inches behind an aircraft model with focus on the rudder showed the ruler scale in focus. Also at infinity the focusing lines did not align on a building 250 metres away. Thanks everyone. Link to post Share on other sites More sharing options...
farnz Posted February 28, 2015 Share #9 Posted February 28, 2015 Is it possible that the 'rough bayonet mount' of the Tele-Elmarit bent the focussing cam or left something behind on the roller? Pete. Link to post Share on other sites More sharing options...
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