elia Posted March 28, 2011 Share #1 Posted March 28, 2011 Advertisement (gone after registration) I have problem with front focusing when lens wide open and distance around meter. It front focusing around 1 cm. I have 3 lenses and all 3 doing the same things. Send to adjustment, no help. Why is that? Link to post Share on other sites More sharing options...
Advertisement Posted March 28, 2011 Posted March 28, 2011 Hi elia, Take a look here problem with front focusing. I'm sure you'll find what you were looking for!
mjh Posted March 28, 2011 Share #2 Posted March 28, 2011 Which lenses wouldn’t tolerate 1 cm of front-focus at 1 m, I wonder? The Noctilux of course, but with the Summilux-M 1:1,4/50 mm Asph., for example, the depth of field at f1.4 would be sufficient to mask the front-focus. Link to post Share on other sites More sharing options...
jaapv Posted March 28, 2011 Share #3 Posted March 28, 2011 Welcome to the forum. However, you cannot expect a coherent answer with such an unspecific question. May I suggest you use the search function first. There are dozens of threads on the subject in this forum. Link to post Share on other sites More sharing options...
elia Posted March 28, 2011 Author Share #4 Posted March 28, 2011 Summilux 1.4 /50 - very easy to see problem Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/147442-problem-with-front-focusing/?do=findComment&comment=1627991'>More sharing options...
jaapv Posted March 28, 2011 Share #5 Posted March 28, 2011 How did you test that? There is no perspective. Anyway, with a rangefinder you need to test on a surface that is parallel to the sensor plane, as the rangefinder patch will show different focus between top and bottom with a test ruler at 45 degrees, which is the normal test rig. Link to post Share on other sites More sharing options...
ho_co Posted March 28, 2011 Share #6 Posted March 28, 2011 Elia, welcome aboard the forum! How well does your camera and lens work in normal picture-taking situations? There's apparently an error with that lens and camera combination, but I don't think it would be possible to discern a mis-focus that small in "real" photography. The rangefinder is a complicated mechanism that needs to track accurately at all distances. To my eye, this is at least "good enough" for a 1-m distance. If you were hand-holding at that distance, just breathing would be enough to shift the focus more than that much. Please tell us more: You say the camera frontfocuses equally at 1 m with three lenses. What three lenses? You say you sent it for adjustment and nothing changed. Who did the adjustment? What did they say about it? Did you discover this "problem" when taking pictures and then buy the LensAlign to test it, or did you need the LensAlign to decide that something might not be perfect? Link to post Share on other sites More sharing options...
elia Posted March 28, 2011 Author Share #7 Posted March 28, 2011 Advertisement (gone after registration) I find problem when I make picture of person. I focus on eye but nose was in focus. I find problem when I make picture of person. I focus on eye but nose was in focus. I send 3 times to leica. Few times after repair focus was even worse. But more that all they scratch screws inside. Link to post Share on other sites More sharing options...
cae Posted March 28, 2011 Share #8 Posted March 28, 2011 Hi Elia Jaapv is of course right, but provided that the test shot is done correctly, it does looke like a problem of more than 1cm... I had the exact same problem with my 50 lux and it was sent to Solms after beeing tested locally by the Norwegian Leica rep. They told me that in the same situation/ picture as the one you show here, only 1/3 of the in-focus area should be in front of your focus point and the remaning 2/3’s behind - for the lens to be on spec. Your picture clearly show «most» in front. I just picked up mine today and hope it is now up to spec.! Has your lenses (the three) been to Solms allready, and no change?? If all 3 are showing the same problem, then it is safe to suggest that the camera is giving you a hard time. R Christian Link to post Share on other sites More sharing options...
elia Posted March 28, 2011 Author Share #9 Posted March 28, 2011 I'm in US and send it to New Jersey. One time after repair focus was closed to original. Also when I purchase I find problem in a week. I come back to store and test another one. I get exactly the same problem. That is why I think it maybe me, but I had tech from another service shop to test and they get the same result as me. Link to post Share on other sites More sharing options...
ho_co Posted March 28, 2011 Share #10 Posted March 28, 2011 Are you close to the New Jersey facility? With this kind of discrepancy, it might be helpful to take the camera in and talk with the people directly. Please pardon one more question: You are certain that your eyes or glasses don't need a prescription update, right? It must be very upsetting for you to have sent the camera for adjustment repeatedly and have it returned without improvement, and then to get all these questions on the forum. Maybe the best thing is for you to call Leica. Ask for customer service. Explain that the camera has already been in unsuccessfully for the same adjustment a couple times. Establish contact, offer to send a file by email to show them what you're talking about. Make them aware how frustrating the camera is becoming, and send it in to the attention of someone aware of your dissatisfaction. I agree with cae that the image you show looks like more than 1 cm error, so maybe it would be better to say "about 2-3 cm," to get them to take a hard look at it. EDIT: BTW, I'm sad to say that it's not uncommon for the screws to be scratched after a rangefinder adjustment. My M8 has the same. But tell them how disappointed you are to have the camera no better after three trips in, and to see that the screws have been damaged to boot. And a question: How easy is it to use the LensAlign with the M? I would have thought it would be pretty hard to use, and would have suggested something like the Nikon D70 Focus Chart instead. Link to post Share on other sites More sharing options...
jaapv Posted March 28, 2011 Share #11 Posted March 28, 2011 I'm in US and send it to New Jersey. One time after repair focus was closed to original. Also when I purchase I find problem in a week. I come back to store and test another one. I get exactly the same problem. That is why I think it maybe me, but I had tech from another service shop to test and they get the same result as me. Did this other guy tell you whether it was the camera or the lens? Link to post Share on other sites More sharing options...
elia Posted March 28, 2011 Author Share #12 Posted March 28, 2011 I'm 2 hours to fly and after that few drive. Frankly I didn’t expect service like that. I send pictures, send my test equipment. All the time very similar result. As well as scratches. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/147442-problem-with-front-focusing/?do=findComment&comment=1628093'>More sharing options...
jrh68uk Posted March 28, 2011 Share #13 Posted March 28, 2011 I wouldn't know why they even touched that one. Isn't it enough to adjust just the roller (allen key, front right) and maybe the arm length (gain adjustment, held in place by the front left screw)? Link to post Share on other sites More sharing options...
elia Posted March 28, 2011 Author Share #14 Posted March 28, 2011 Did this other guy tell you whether it was the camera or the lens? I send them all 3 lenses and camera. They told me that 2 of lenses were out of spec. I pick 2 used ones and 1 new. So out of spec were used and new. They test it together. Now I'm questioning did they done good job with my lenses? Link to post Share on other sites More sharing options...
bocaburger Posted March 28, 2011 Share #15 Posted March 28, 2011 If you have 3 lenses and all of them front focus by the same amount, I don't understand how only 2 of them could be out of spec (unless the specs on the 3rd one are more lenient ). When I got my M9 it front focused the same with 11 out of 12 lenses. I adjusted the rangefinder myself (close-focus, aka "gain", aka "arm length" and then readjusted infinity). At that point the 11 lenses focused spot-on, and the one that had focused well before was now back-focusing the same amount. I sent that one to DAG, who found that it was indeed back-focusing with his test equipment. It is now returned to me and focusing perfectly. Oh, and there are no gored screws on my camera either...and if an "amateur" like myself could do the job without leaving telltale damage, one would think the "pro" in Allendale could, too. Link to post Share on other sites More sharing options...
elia Posted March 28, 2011 Author Share #16 Posted March 28, 2011 If you have 3 lenses and all of them front focus by the same amount, I don't understand how only 2 of them could be out of spec (unless the specs on the 3rd one are more lenient ). When I got my M9 it front focused the same with 11 out of 12 lenses. I adjusted the rangefinder myself (close-focus, aka "gain", aka "arm length" and then readjusted infinity). At that point the 11 lenses focused spot-on, and the one that had focused well before was now back-focusing the same amount. I sent that one to DAG, who found that it was indeed back-focusing with his test equipment. It is now returned to me and focusing perfectly. Oh, and there are no gored screws on my camera either...and if an "amateur" like myself could do the job without leaving telltale damage, one would think the "pro" in Allendale could, too. As I understand it is camera problem. Even after they adjust lenses i still get the same result. I would worry too much about screws but I expect for 7k at least that repair done right. I have it for 5 month and 3 of them this camera been at Leica repair center. Link to post Share on other sites More sharing options...
mjh Posted March 28, 2011 Share #17 Posted March 28, 2011 They told me that in the same situation/ picture as the one you show here, only 1/3 of the in-focus area should be in front of your focus point and the remaning 2/3’s behind - for the lens to be on spec. At distances close to the near limit, the depth of field extends equally in front of and behind the focused distance. Checking Leicas specs for the Summilux-M 50 mm, the depth of field at 1 m and f1.4 should range from 0.984 m to 1.016 m, i.e. 16 mm in front and 16 mm behind. Link to post Share on other sites More sharing options...
cae Posted March 29, 2011 Share #18 Posted March 29, 2011 At distances close to the near limit, the depth of field extends equally in front of and behind the focused distance. Checking Leicas specs for the Summilux-M 50 mm, the depth of field at 1 m and f1.4 should range from 0.984 m to 1.016 m, i.e. 16 mm in front and 16 mm behind. Thanks, I have checked mine now and it seems that it does exactly that; the chosen focus point is in the middle of DOF. I have one question though - was the Leica rep here in Oslo wrong, or is the "1/3 in front and 2/3’s behind focus point», the goal on longer distances? Regards Christian Link to post Share on other sites More sharing options...
mjh Posted March 29, 2011 Share #19 Posted March 29, 2011 I have one question though - was the Leica rep here in Oslo wrong, or is the "1/3 in front and 2/3’s behind focus point», the goal on longer distances? There is just one distance (1/3 of the hyperfocal distance) for which this is true. Link to post Share on other sites More sharing options...
Guest #12 Posted April 24, 2011 Share #20 Posted April 24, 2011 ...with a rangefinder you need to test on a surface that is parallel to the sensor plane, as the rangefinder patch will show different focus between top and bottom with a test ruler at 45 degrees, which is the normal test rig. I'm not sure what you mean; the two points on the ruler at 45 deg. are different distances from the camera, so they should show different focus. If you mean there is an error from using the edge of the patch to focus, compared to the center--I've heard that before, but not seen any rationale or practical demonstration. If you mean there is an error from using an oblique target, I've heard that one too, but not seen any rationale or practical demonstration. Link to post Share on other sites More sharing options...
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