povlj Posted May 31, 2011 Share #1 Posted May 31, 2011 Advertisement (gone after registration) I'm new M9 owner and am out getting to know this delightful camera. Am shooting with my 50mm 1.4 Summilux. This lens is great at mid range apertures and medium distances, but I am finding a problem: When I open aperture fully, to 1.4, and turn distance to Infinity, images are not in sharp focus when enlarged, even moderately; focus improves as I reduce aperture, but image enlarged remains a bit fuzzy even at f/16. In contrast, when I shoot an object at intermediate distance, like 5 meters, image is razor sharp at all apertures. I'm certainly not a lens expert, but is something wrong with my Summilux? Help, please. Povl Link to post Share on other sites More sharing options...
Advertisement Posted May 31, 2011 Posted May 31, 2011 Hi povlj, Take a look here Focus on 50mm Summilux. I'm sure you'll find what you were looking for!
!Nomad64 Posted May 31, 2011 Share #2 Posted May 31, 2011 There's nothing wrong with the lens. Most likely there's some rangefinder trimming to be done in respect of infinity focusing. Cheers, Bruno Link to post Share on other sites More sharing options...
povlj Posted June 1, 2011 Author Share #3 Posted June 1, 2011 Any other opinions? Link to post Share on other sites More sharing options...
lars_bergquist Posted June 1, 2011 Share #4 Posted June 1, 2011 I own the lens since 2005, and before me lie the MTF charts. At full aperture, the telltale curve for 20 line-pairs/millimeter lies at slightly below 80% on axis and out to an image height of about 15mm. This value is pretty sensational for this aperture. It is in fact just as good as the performance of the 50mm Summicron, current model. – The axial value is pretty well the same for the predecessor Summilux, but off axis, it drops really fast. The curve rises to over 90% at 2.8, and 95–97 at 5.6. So, even with perfect adjustment of both rangefinder and lens, you cannot expect the same definition at 1.4 as when stopped down. I don't expect it, for sure. These are facts of life. This of course does not mean that errors are excluded, but I mention this for perspective, and proportion. A sense of proportion is the essence of sanity. It should be added that true mathematical infinity is a physical impossibility. Not even the most distant galaxy is infinitely distant. What may be called 'technical infinity' is a distance roughly equal to 1,000 times the focal length, in this case 50m. If you do infinity testing at greater distances, you risk complicating the results with extraneous factors such as haze, mirage or even the very existence of the atmosphere itself – it is by no means as transparent as we tend to think! The old man from the Age of the 5cm Elmar Link to post Share on other sites More sharing options...
jaapv Posted June 1, 2011 Share #5 Posted June 1, 2011 Lars is right.However if you feel doubt have the focusssing of the lens checked by either Leica or a specialist Link to post Share on other sites More sharing options...
Lindolfi Posted June 1, 2011 Share #6 Posted June 1, 2011 It has not become clear from the original poster wether he meant turning the focus ring of the summilux all the way to infinity and taking a picture of a very far away object (beyond 1 kilometer) or that he used the rangefinder taking a picture of that objcect. That makes all the difference where to look for when finding the answer to his question. Link to post Share on other sites More sharing options...
luigi bertolotti Posted June 1, 2011 Share #7 Posted June 1, 2011 Advertisement (gone after registration) When one deals about infinity, it's easy to intermix the concepts of "sharpness" and "on focus"... as Lars said, a very FAR image can look "unsharp" (even if it IS on focus) for many reasons... atmosphere I think it's the main factor. For testing infinity focus, i find that most useful do-it-yourself tests are big city advertising panels, with letters, taken at 50-100 meters (in case of lenses around 35 to 90 mm) Link to post Share on other sites More sharing options...
01af Posted June 1, 2011 Share #8 Posted June 1, 2011 I own the lens since 2005 ... I wonder which lens you are talking about ... and which lens you're thinking povljorgensen was talking about. It should be added that true mathematical infinity is a physical impossibility. Not even the most distant galaxy is infinitely distant. Here, you are confusing infinite distance with infinity focus setting. The latter is perfectly possible with mathematical precision ... as a matter of fact, you can even focus beyond infinity. Infinity setting is achieved when the incoming rays are parallel for each image point. And this setting makes sense for (long but finite) distances where any other setting would yield no better image. What may be called 'technical infinity' is a distance roughly equal to 1,000 times the focal length, in this case 50 m. If you do infinity testing at greater distances, you risk complicating the results with extraneous factors such as haze, mirage or even the very existence of the atmosphere itself—it is by no means as transparent as we tend to think! That's correct basically ... except 50 m still is too short to be considered technical infinity for a fast 50 mm lens at full aperture. Make that 100 or 150 m ... or maybe even 200 m. The better the lens, the farther away infinity is. Link to post Share on other sites More sharing options...
povlj Posted June 1, 2011 Author Share #9 Posted June 1, 2011 I used the lens to take picture of dance recital on stage, about 100 meters away. Link to post Share on other sites More sharing options...
povlj Posted June 1, 2011 Author Share #10 Posted June 1, 2011 When one deals about infinity, it's easy to intermix the concepts of "sharpness" and "on focus"... as Lars said, a very FAR image can look "unsharp" (even if it IS on focus) for many reasons... atmosphere I think it's the main factor. For testing infinity focus, i find that most useful do-it-yourself tests are big city advertising panels, with letters, taken at 50-100 meters (in case of lenses around 35 to 90 mm) Thanks for the suggestion; I shall try that, Looking at some recent shots, it is evident that when focusing on objects about 15 meters distant, at f/11 or so, objects far away, ie "infinity", come out very sharp. Strange, despite what Lars says. But I really appreciate all the fine suggestions here -- this is a great forum for rank amateurs like me. Povl Link to post Share on other sites More sharing options...
lars_bergquist Posted June 1, 2011 Share #11 Posted June 1, 2011 Here, you are confusing infinite distance with infinity focus setting. The latter is perfectly possible with mathematical precision ... as a matter of fact, you can even focus beyond infinity. Infinity setting is achieved when the incoming rays are parallel for each image point. And this setting makes sense for (long but finite) distances where any other setting would yield no better image. My point was exactly the difference between the purely mathemathical concept of infinity, and physical reality. And yes, you can focus beyond 'optical infinity' – that's what my old eyes do when I remove my specs! That's correct basically ... except 50 m still is too short to be considered technical infinity for a fast 50 mm lens at full aperture. Make that 100 or 150 m ... or maybe even 200 m. The better the lens, the farther away infinity is. Now you're picking nits. We are speaking of a test anyone can do, not having an optical bench in the basement ... The old man Link to post Share on other sites More sharing options...
lars_bergquist Posted June 1, 2011 Share #12 Posted June 1, 2011 Thanks for the suggestion; I shall try that, Looking at some recent shots, it is evident that when focusing on objects about 15 meters distant, at f/11 or so, objects far away, ie "infinity", come out very sharp. Strange, despite what Lars says.Povl In that case, and if the effect is consistent, I would suspect misadjustment of either the lens or the rangefinder. Or – pardon me – a consistent pilot error. In that case, only trial – feedback – trial feedback can help. The old man Link to post Share on other sites More sharing options...
250swb Posted June 1, 2011 Share #13 Posted June 1, 2011 I used the lens to take picture of dance recital on stage, about 100 meters away. 100 meters away is not infinity. And as it was a dance recital it may be worth asking what shutter speed you were shooting at, just in case there is a connection between that and blurred photo's. Steve Link to post Share on other sites More sharing options...
wizard Posted June 1, 2011 Share #14 Posted June 1, 2011 At true infinity, say everything beyond 200 meters, a current Summilux 50 asph (assuming that is the lens everyone is talking about here) set to infinity will be razor sharp even at full aperture (further assuming we do not have any motion involved, neither at the subject side nor at the camera side). Mine is for sure. Andy Link to post Share on other sites More sharing options...
thighslapper Posted June 1, 2011 Share #15 Posted June 1, 2011 I had the same problem with an 'as new' but pre 6 bit coding 50/1.4 asph. With viewfinder magnification the images never coincided when the lens was set to infinity.... and at wide apertures distant objects were never exactly in focus. I have just bought a second genuinely 'as new' which is unused and only 9 months old and the rangefinder coincidence at infinity and the images are spot on. I would find someone or a Leica dealer with a demo 50/1.4 and try some test shots with that. I think you will find it is the lens. Wide open this lens is very unforgiving of calibration errors ... both of rangefinder and lens.... My 'spare' 50/1.4 is going off to Malcolm Taylor to be brought up to spec. Link to post Share on other sites More sharing options...
povlj Posted June 1, 2011 Author Share #16 Posted June 1, 2011 In that case, and if the effect is consistent, I would suspect misadjustment of either the lens or the rangefinder. Or – pardon me – a consistent pilot error. In that case, only trial – feedback – trial feedback can help. The old man LarsP: You may be very right, it could be pilot error. Will go testing it all in next few days to find out for sure if it is equipment or operator. Need to know as we are going to Alaska in August and I plan to use my M9 to its fullest, both 50 mm and 90 mm ASPH lenses. Povl Link to post Share on other sites More sharing options...
povlj Posted June 1, 2011 Author Share #17 Posted June 1, 2011 I had the same problem with an 'as new' but pre 6 bit coding 50/1.4 asph. With viewfinder magnification the images never coincided when the lens was set to infinity.... and at wide apertures distant objects were never exactly in focus. I have just bought a second genuinely 'as new' which is unused and only 9 months old and the rangefinder coincidence at infinity and the images are spot on. I would find someone or a Leica dealer with a demo 50/1.4 and try some test shots with that. I think you will find it is the lens. Wide open this lens is very unforgiving of calibration errors ... both of rangefinder and lens.... My 'spare' 50/1.4 is going off to Malcolm Taylor to be brought up to spec. Who is Malcolm Taylor and how do I contact him? Link to post Share on other sites More sharing options...
jamesk8752 Posted June 2, 2011 Share #18 Posted June 2, 2011 Who is Malcolm Taylor and how do I contact him? Malcolm is in the UK; as your profile indicates that you are in the USA you'd be better served timewise sending your lens to Leica in NJ or to an independent Leica service shop such as Golden Touch (Sherry Krauter), DAGCam (Don Goldberg), or Focal Point (John Van Skelten). You can google them to find phone and/or email contact info. Regards, Jim Link to post Share on other sites More sharing options...
andybarton Posted June 2, 2011 Share #19 Posted June 2, 2011 There is a link to repair specialists at the top of this Customer sub-forum Link to post Share on other sites More sharing options...
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