joeswe Posted August 2, 2012 Share #1 Posted August 2, 2012 Advertisement (gone after registration) When my M3 developed a problem with the film transport this year I had it serviced at a very well regarded repair shop and also told them that the range finder was off at close distance, because I had noticed that most of my shots with the Summilux at large apertures where consistently focused a bit behind the intended point. A month ago, the camera returned after a full CLA but last week I noticed it is still focusing behind the intended point of focus. I had the lens checked on a collimator before and it turned out okay... So I set up a test and shot the M3 with all my M lenses wide open at closest distance (just above 1 m). The results showed that only one lens (Elmar-M 90 at f4) had the focus spot barely within the plane of acceptable sharpness. All other lenses were focused a couple of centimeters behind the focus mark, with the focus mark more or less unsharp. Of course I used a tripod and took 3 pics with every lens, refocusing for every shot, the results were very consistent. So, for me it appears as if the rangefinder of the M3 is still off. Is it worth returning the camera to the repair shop for readjustment or would you say I am expecting too much at the limits of the rangefinder system on the M3 and should bear with it? 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/184913-rangefinder-focus-accuracy-am-i-expecting-too-much/?do=findComment&comment=2077431'>More sharing options...
Advertisement Posted August 2, 2012 Posted August 2, 2012 Hi joeswe, Take a look here Rangefinder focus accuracy - am I expecting too much?. I'm sure you'll find what you were looking for!
Michael Geschlecht Posted August 2, 2012 Share #2 Posted August 2, 2012 Hello joeswe, It looks like all the lenses, including the Elmar-M @ F4, are misfocussing more or less the same ammount. I would have the rangefinder checked. A properly calibrated M3 is able to focus more accurately than any other M. Best Regards, Michael Link to post Share on other sites More sharing options...
fotohuis Posted August 2, 2012 Share #3 Posted August 2, 2012 Exactly, re-calibrate the RF. Link to post Share on other sites More sharing options...
Messsucherkamera Posted August 2, 2012 Share #4 Posted August 2, 2012 Does the rangefinder mechanism have to be calibrated for a specific lens to ensure optimal focus accuracy? If so, what happens when you use a different lens - is the RF off? If the above is true, it seems like a person in search of optimal focusing accuracy would need one M body, calibrated for a specific lens, for each lens they own. That's not the case - is it?? Link to post Share on other sites More sharing options...
250swb Posted August 2, 2012 Share #5 Posted August 2, 2012 That's not the case - is it?? No, fortunately it is not the case. Steve Link to post Share on other sites More sharing options...
andybarton Posted August 2, 2012 Share #6 Posted August 2, 2012 Calibrate the lenses and the camera body to factory standards and they will all work properly together and with other properly calibrated bodies or lenses. Leica do not calibrate a particular body for a particular lens. That way, madness lies. Link to post Share on other sites More sharing options...
Michael Geschlecht Posted August 2, 2012 Share #7 Posted August 2, 2012 Advertisement (gone after registration) Hello Andy, Altho that is how Leitz's lenses for the Leica were 1st calibrated back in 1930. Fortunately, NOT the case since 1931. Best Regards, Michael Link to post Share on other sites More sharing options...
Messsucherkamera Posted August 2, 2012 Share #8 Posted August 2, 2012 Calibrate the lenses and the camera body to factory standards and they will all work properly together and with other properly calibrated bodies or lenses. Leica do not calibrate a particular body for a particular lens. That way, madness lies. That's what I thought. Link to post Share on other sites More sharing options...
joeswe Posted August 3, 2012 Author Share #9 Posted August 3, 2012 Thank you everybody for your input. I will return the camera to the repair shop for re-calibration. Link to post Share on other sites More sharing options...
Scarlet Posted August 3, 2012 Share #10 Posted August 3, 2012 Joe, does your photos appear out of focus? I mean, perhaps the focus shift is within the tolerances of film. Naturally, though, if you want you should have it checked. I'm just trying to save you a trip to the shop. Link to post Share on other sites More sharing options...
Rolo Posted August 3, 2012 Share #11 Posted August 3, 2012 Before you start sending cameras around the world, can I suggest you get your local glazier to supply a small piece of 'ground glass', or slightly frosted glass to enable you to inspect the sharpness of each lens directly. Should be obvious what I'm suggesting from the photos. But for the comfort of the written word: Ground glass should be slightly bigger than the 35mm frame so it can sit comfortable across the film rails Using an optical target, using a tripod supported camera with it's back gate open, focus the camera RF on the target using the viewfinder. Inspect the focus with the ground glass screen using a locking cable release and the B shutter setting. With a magnifier, you'll be able to clearly see exactly what the lens is focussed on and spot any focussing errors. Take a few as your RF setting is a subjective decision and it will vary from frame to frame. Average a number (say 10) of readings for each lens and average them. Look for patterns with your different lenses and if it's the rangefinder it'll show a tendency to skew the readings to one side. If they're out, but not in one direction, then I'd send bodies and lenses back to Solms so that the body can be set to a standard and the lenses adjusted to suit. When I had my M9s calibrated, I sent my film bodies with them and the whole set was adjusted to perfection. When calibrated, the RF is not necessarily sorted for life and it's possible for it to change through knocks and bangs in the bag, but you should spot that in use and now be able to confirm accuracy using the above. You can also use the ground glass in the same way, whilst adjusting the rangefinder setting. 10 pence, please. 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/184913-rangefinder-focus-accuracy-am-i-expecting-too-much/?do=findComment&comment=2078545'>More sharing options...
andyedward Posted August 3, 2012 Share #12 Posted August 3, 2012 Rolo, Many Thanks for sharing such an ingenious solution! I'm sure it will come in useful for me in future (if my MP ever arrives......) Link to post Share on other sites More sharing options...
pico Posted August 3, 2012 Share #13 Posted August 3, 2012 Rolo: Before you start sending cameras around the world, can I suggest you get your local glazier to supply a small piece of 'ground glass', or slightly frosted glass to enable you to inspect the sharpness of each lens directly. Focusing on a ground glass is okay, but for critical testing you might consider aerial or parallax focusing. For aerial focus a hole (10mm is good) is drilled through the ground glass and a hair (or cross hair) or very fine wire is placed on the ground side (toward the lens) and a high-power magnifier is best (8x or 10x). For parallax focusing just polish away a spot of the ground glass; a normal magnifier (4x) is adequate. I will look for an instructional source later today. It the film equivalent to digital pixel-peeping. When you get the hang of it, it's pretty quick and easy. An engineer at work tried to get me interested in using a Ronchi grate but it drove me crazy, and they are expensive. Link to post Share on other sites More sharing options...
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