wslam Posted December 3, 2009 Share #1 Posted December 3, 2009 Advertisement (gone after registration) I got a second hand 75 Cron today, manufactured in 2005. Anyway, it seems that there is significant focus shift when I focus up close. At the closest focusing distance, it seems to be roughly 1 in off! Given the shallow DOF wide open at closest focusing distance, this renders the lens useless! Focus at the 2 ft mark: Is this something others have experienced or is the 75 Cron I got is a dud? Is focus shift something that can be serviced? Thank you in advance. ws Link to post Share on other sites More sharing options...
Advertisement Posted December 3, 2009 Posted December 3, 2009 Hi wslam, Take a look here Anyone has focus shift issue with 75 Cron on M9?. I'm sure you'll find what you were looking for!
jaapv Posted December 3, 2009 Share #2 Posted December 3, 2009 Focus shift is something else, that is a shifting of the plane of focus as you close down the aperture. Your lens simply misfocusses at short distance, something that good Leica repair shops can fix for you. Link to post Share on other sites More sharing options...
wattsy Posted December 3, 2009 Share #3 Posted December 3, 2009 Don't confuse front or back focus with focus shift. The latter is when the point of focus moves as you close down the aperture. The problem you seem to have is that your lens is front focussing. It is something that can be adjusted but I would conduct further tests before concluding that there is anything wrong with the calibration of the lens or body. Link to post Share on other sites More sharing options...
michali Posted December 3, 2009 Share #4 Posted December 3, 2009 I use a 75 Summicron on my M9 with no issues. However my 135mm APO-TELYT was back focusing and I sent it to Leica in Germany who fixed it for free. Your lens seems to be front focusing; this can be fixed. Having bought it only yesterday I would suggest that you return it and ask for an exchange or ask the seller to arrange for it to be adjusted. Link to post Share on other sites More sharing options...
wslam Posted December 3, 2009 Author Share #5 Posted December 3, 2009 Thank you. Indeed, I meant to say Front Focusing, not focus shift. Thank you for the verification. Is it customary to send all the lenses AND the body to Leica for calibration? I tried my other lenses (Trielmar (impossible to tell), 35 and 50 Cron, and a 50 Noct (0.95). Is there a controlled method to find out whether it's the lens or body that is causing the front focusing? Link to post Share on other sites More sharing options...
michali Posted December 3, 2009 Share #6 Posted December 3, 2009 Is it customary to send all the lenses AND the body to Leica for calibration? I tried my other lenses (Trielmar (impossible to tell), 35 and 50 Cron, and a 50 Noct (0.95). Is there a controlled method to find out whether it's the lens or body that is causing the front focusing? I checked my 135mm on 3 different bodies (M8, M8.2 & M9) all with the same result.....so therefore it could only be the lens. In addition all of my other other lenses focused spot on. If you're not picking up focus issues with your other lenses then it's not the body, so IMO it's not necessary to send the body in. Link to post Share on other sites More sharing options...
wslam Posted December 3, 2009 Author Share #7 Posted December 3, 2009 Advertisement (gone after registration) Mike, unfortunately I do not have 3 M bodies to try my lenses on as the M9 is my first digital Leica. I do have a M7, but that will not really simplify the verification process... Link to post Share on other sites More sharing options...
jaapv Posted December 3, 2009 Share #8 Posted December 3, 2009 Thank you. Indeed, I meant to say Front Focusing, not focus shift. Thank you for the verification. Is it customary to send all the lenses AND the body to Leica for calibration? I tried my other lenses (Trielmar (impossible to tell), 35 and 50 Cron, and a 50 Noct (0.95). Is there a controlled method to find out whether it's the lens or body that is causing the front focusing? No - the lens will be calibrated to a standard body. It might be a good idea to have it done by a good camera workshop instead of Leica, though. Link to post Share on other sites More sharing options...
wslam Posted December 3, 2009 Author Share #9 Posted December 3, 2009 No - the lens will be calibrated to a standard body. It might be a good idea to have it done by a good camera workshop instead of Leica, though. What is the advantage to ask a third party to calibrate? Thanks. ws Link to post Share on other sites More sharing options...
cgthanos Posted December 3, 2009 Share #10 Posted December 3, 2009 I had the exact same issue on my 75 cron / m9, but then I went through all of my lenses at 35 mm or greater (35 lux, 50 cron, 50 lux, 50 nokton) and realized that it was the rangefinder, as all of the lenses front-focused by a couple of centimeters. For me, the issue was manifested most by the 75 cron, as it should be, and it was only after my first shoot with it that I started looking at the entire system. A calibration of the rangefinder has resulted in perfect performance with all of the lenses, especially in a real world setting (particularly eyes in portraits). You have probably already done so, but I would recommend ruling out the rangefinder before you send the 75 in. Link to post Share on other sites More sharing options...
jaapv Posted December 3, 2009 Share #11 Posted December 3, 2009 What is the advantage to ask a third party to calibrate? Thanks. ws Price and speed. Link to post Share on other sites More sharing options...
Alnitak Posted December 3, 2009 Share #12 Posted December 3, 2009 Definitely speed. I have an M8.2 in with Leica USA for repairs, and they have a two month backlog right now! My 75 'cron also frontfocuses and I am going to get it adjust locally. Link to post Share on other sites More sharing options...
wslam Posted December 3, 2009 Author Share #13 Posted December 3, 2009 Usually how much does it cost to have the focus recalibrate? Link to post Share on other sites More sharing options...
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