twom4 Posted April 23, 2011 Share #1 Â Posted April 23, 2011 Advertisement (gone after registration) Dear All, Â Has anyone experienced back focus on Summicron 75 Apo ASPH at a longer distant of around 8-10 metre mark, aperture F2.0, using Leica M9? I recently noticed this occurrence. Close focus of around 1m is accurate. Â Any comment or input as to what I need to do to rectify this? Â Thank you in advance. Link to post Share on other sites More sharing options...
Advertisement Posted April 23, 2011 Posted April 23, 2011 Hi twom4, Take a look here Summicron 75mm Apo ASPH - Back Focus. I'm sure you'll find what you were looking for!
erl Posted April 23, 2011 Share #2 Â Posted April 23, 2011 First step, if you have access to other lenses, run tests on the body with those other lenses, at all apertures and a range of distances. This is to determine if the M9 is focussing OK, as well as the other lenses. Repeat for the 75mm while you are at it. Make sure you use a tripod and try to set up/use a clear focus target like a picket fence with one picket marked in some way. Range from min. focus dist. to say 30m or more. Be deliberate about focussing each time. View the results on the computer, not the LCD. Link to post Share on other sites More sharing options...
Revdockj Posted April 23, 2011 Share #3 Â Posted April 23, 2011 It turns out both my new 75 cron and my M9 had focusing issues. I had to have both of them adjusted. Â Ken Link to post Share on other sites More sharing options...
hoppyman Posted April 24, 2011 Share #4  Posted April 24, 2011 Hi Chris. I have no problems with this lens on my M9 and earlier M's. Actually it is my favourite and that precision and ability to isolate the most important element is one of the reasons for me. Adrienne confronts Lisette photo - Geoff Hopkinson photos at pbase.com Careful pour photo - Geoff Hopkinson photos at pbase.com  As Erl suggested you may wish to do some careful testing to be sure exactly what is going on.  The Leica depth of field tables quote nearly 600mm of depth of field (@f/2) at 5 metres so there is more at 8 to 10 metres of course. Are you seeing the focus as visibly outside that altogether or you feel that it is back focus within that depth?  At one metre the quoted DoF figure is only 21mm and you are happy that your focus is correct there? Dear All, Has anyone experienced back focus on Summicron 75 Apo ASPH at a longer distant of around 8-10 metre mark, aperture F2.0, using Leica M9? I recently noticed this occurrence. Close focus of around 1m is accurate.  Any comment or input as to what I need to do to rectify this?  Thank you in advance. Link to post Share on other sites More sharing options...
twom4 Posted April 24, 2011 Author Share #5 Â Posted April 24, 2011 Dear All, Â Thank you for your inputs and comments. Â At close distance, the focus is accurate. At beyond 5 meters it back focus by about 30 cm (i.e. although I focus at a point, the sharpness occurred about 30 cm behind it - consistently). Â As suggested, I will do careful test in a couple of weeks or as soon as time permit. Â I only found out about it recently as I usually take picture of subjects within 2 - 3 meters. Â The thought of parting with either the lens or M9 for a few months is not comforting. Â As soon as I have done the test, I will report the result back. Thanks again. Link to post Share on other sites More sharing options...
erl Posted April 24, 2011 Share #6 Â Posted April 24, 2011 Chris, if you are confident that there is a problem, I suggest the sooner you make plans to have it adjusted the better. Until then, you can never be confident about your picture results. Bite the bullet and be without your gear sooner rather than later. Link to post Share on other sites More sharing options...
twom4 Posted April 28, 2011 Author Share #7 Â Posted April 28, 2011 Advertisement (gone after registration) Hi Erl, Â As soon as I am done with comprehensive test and can conclude the results, I will send the lens and/or the M9. Â Thanks. Link to post Share on other sites More sharing options...
hydeca Posted April 28, 2011 Share #8 Â Posted April 28, 2011 Has anyone experienced back focus on Summicron 75 Apo ASPH at a longer distant of around 8-10 metre mark, aperture F2.0... Â Not with a Summicron 75 (I don't own one) but with an Elmarit 28 ASPH yes. The lens is back focusing so badly that the focus ring has to be set to 10 metres for infinity! This is not the sort of manufacturing defect I would expect of a new Leica lens, nor would I expect such a defect to go undetected during quality control procedures. Â I see Ken had this problem with a Summicron 75 too. That plus the shutter failure on my M9 is beginning to erode my confidence in the quality of recently manufactured Leica products. Â Nevertheless both products are under warranty so apart from the inconvenience of being without the gear for a few weeks/months its just a matter of sending the stuff off to Solms for repair/replacement. Link to post Share on other sites More sharing options...
Swanny66 Posted April 28, 2011 Share #9 Â Posted April 28, 2011 I have a 75 cron ASPH and it is very sharp. It does take a bit to learn to get the focus accurate with the longer lenses. I am very happy with my lens on the M9. But I agree with the testing. If you are hand holding that close, and the DOF is that shallow, any tiny movement after focus would have an impact on sharpness I would think. Link to post Share on other sites More sharing options...
vanhulsenbeek Posted April 29, 2011 Share #10 Â Posted April 29, 2011 Same for me, after adjustment (which was free as in the M9 warranty period) and I sent in both lens and camera. The 75 Summicron seems to be at the edge of rangefinder possibilities. Takes training and then some luck to get tack-sharp pictures. But boy, are they good then:) Link to post Share on other sites More sharing options...
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