Summicron 50 woes after service
Old 10-10-2018   #1
lukx
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Summicron 50 woes after service

Hi folks,

I am having trouble with my Summicron after I had it serviced together with my M2.
The M2 received a CLA, it seems fine. The lens had an oily dust-speck that was removed, the aperture blades were cleaned.

After I received it back, I noticed that the rangefinder patch does not align at infinity. It focuses short, not beyond infinity. I did not try the moon, but if it falls short on targets 2-3 miles away, it should also fall short with the moon. Also I noticed that the resistance of the otherwise smooth focusing ring felt a little uneven near infinity. A little 'scratchy' maybe.

I tested the lens on another body (M6) and compared it to other lenses. The alignment issue was the same on both cameras, and other lenses moved the rangefinder into proper alignment on both cameras. I did not take photos with both cameras. Just checked rangefinder alignment. What I take from this test is that it must be the lens cam and not the rangefinder of the M2 that is off.

I asked my service man (supposedly a reputable guy here in Berlin) about it. He said he only cleaned the optics, and hadn't touched the focusing helicoid. And he said he tested the focus scale for accuracy, finding no issues with the lens. i.e. the distance scale indicates the correct focusing distances.

After closer (re-)inspection he proceeded to claim that the lens cam that moves the rangefinder had been ground down, possibly by a former owner or unskilled repairman. I took this for the truth and went home, devastated because my lens was possibly beyond repair (apparently replacing the cam is something only Leitz can do, he won't get the parts. And a proper Leitz service would be more expensive than buying another used Summicron 50 v3.)

I then compared the lens cam of the Summicron with other Leitz lenses I currently possess. They all look very similar, the brass of the cam is ever so slightly carved down in the area where the rangefinder arm touches the cam surface. The surface is never 100% even/flush. I hope you understand what I am trying to describe here, I have put some macro images of the rangefinder cam in an imgur album. All of these are images of the same lens, the Summicron.

https://imgur.com/a/9kxfQaZ

Anyway, with that being the case, his theory on why the rangefinder was off should not be true.
My initial fear was that if the whole focusing mechanism was off, I'd over-compensate at all distances and focus past my subject to see proper alignment in the viewfinder. But my test images do not seem to indicate such behavior.
I have done some test shots between minimum focusing distance and two meters, and some in the 30 to 50m range and then about 5 km away at f5.6. All shot on APX100. See images attached. It seems fine at close and medium distances. With long distances it’s a little harder to tell; the day was a bit foggy. But to my eye, it does look washed out and not sharp at the subject (the tv tower in the far background) at proper infinity. Instead, the focus seems to be on the lanterns at medium distance.
I could test the lens on my digital Fuji using my cheap M adapter, but I do not trust these adapters. I have read that they often have a slightly short flange distance in order to ensure proper infinity focus.

My current theory is that the cam itself is fine, and that the lens does focus correctly according to its scale. The reason for the misalignment in the viewfinder at infinity and the sub-optimal sharpness at far distances would then be caused by a premature stop of the focus ring. Thus, the lens simply never reaches true infinity. This could be correlated to the slightly 'off' feeling of the focusing ring when approaching infinity. Also, as seen on the last image in my album, the focus indicator on the distance scale seems to stay a little to the left of the infinity mark.

Have you experienced similar issues with a rangefinder lens?
Do you see any issues with the rf cam?
What ways are there to further narrow down the issue?
Do my analysis of the issue and the conclusion that I draw make sense?
Is it possible that the lens helicoid stops turning before it reaches infinity?
My mistake in all of this: I have not thoroughly tested the lens before handing it in for cleaning. I am quite sure that the rangefinder alignment at infinity had been better before and I cannot recall the slight change of turning resistance toward infinity. But I did not consciously check and take notes. Lesson learned!

Should I enforce my warranty rights and have him take it apart again?
I do not want to do him injustice, since I am not 100% certain of the condition of the lens before repair. At the same time I have lost faith in his judgement to a certain extent after his comment regarding the supposed damage of the lens cam. Also, he also did not do his best work on the aperture ring, as at first the front ring was loose, and then, after tightening, the dot indicating the selected aperture is off to the left. See images. Not very convincing.

Last edited by lukx : 10-10-2018 at 05:42. Reason: Black font
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Old 10-10-2018   #2
Papercut
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First of all, sorry for your lens woes!

Second, black text on grey background is hard to read. I had to highlight the entire post (which inverts the font colors) in order to read it.

Third, I personally would send the lens to someone else for a second opinion and repair. Do you really want someone who has potentially botched the job (and then potentially fed you a line to cover up his error!) doing work on it again? Especially if he is annoyed at having you not believe him and enforce your warranty rights? I sure wouldn't; I would be sending it to a different repair person. But, that's just me. Your calculus might be entirely different.
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Old 10-10-2018   #3
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Black text on black background is awesome...

I have done CLA on some RF lenses. If infinity mark couldn't be reached and lens is soft on infinity, it means it was not assembled properly.
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Old 10-10-2018   #4
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I guess i failed the monitor test..
send smoke signals..
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Old 10-10-2018   #5
lukx
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Sorry for the extravagant font color. It should be fixed now. I use the light grey theme and it seemed fine when I posted.
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Old 10-10-2018   #6
Erik van Straten
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If your lens is not sharp at infinity (put on infinity without looking at the rangefinder) but the sharpness is closer, the problem is in the lens, not in the camera.

It is possible that the lens is shimmed (thin pieces of metal are put between the optical part of the lens and the focusing mount of the lens to bring the optics in the right position). If that is done wrongly (if the shim is too thick) the lens will not be sharp at infinity. That will be an easy repair however: remove the shims.

If the lens shows the same deviation on different cameras, the above will be the case.

Otherwise it has left the factory with this deviation. Unprobable.

Erik.
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Old 10-10-2018   #7
:: Mark
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Quote:
Originally Posted by Erik van Straten View Post
Otherwise it has left the factory with this deviation. Unprobable.
My 50mm Summilux has never quite reached rangefinder convergence at infinity. But the images seem perfectly in focus at all distances and apertures, so while it is annoying I am loath to get it repaired...
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Old 10-10-2018   #8
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I had similar problem with a 35mm Summilux Pre-asph, as stated already it was the shims in the lens two camera repair people tried to fix it and couldn't. I eventually fixed myself after finding some info on the web about the shims. After that it was just a case of trial and error changing the shims around until suddenly it just worked!
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Old 10-10-2018   #9
Ronald M
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Pray he was not the one who ground the cam.

Maybe he lost the shim and substituted what he had .

He the lens came to me for repair in "strange condition", I would not work on it without special consent of owner.

Without digging out my lens, I can tell you the last 4 numbers of the serial are hand engraved inside the focus mount. This is to insure the true focal length matches the true measured "throw of focus mount." If they do not match, nobody can fix it. Unscrew the optical unit and check. All lenses with removable optics are mated this way. This was for my Rigid Summicron. yours is the next version and there seam to be no mating numbers. However the little "dip" on the cam is not there. Someone screwed this lens up.

Leica probably will not work on it as there are no parts.

Never buy used that needs repair. You never know what is wrong. Have the seller repair it first.
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Old 10-10-2018   #10
olifaunt
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I can only sympathize. I had a camera serviced and made the mistake of including the lens even though nothing was wrong with it. The top mint vintage lens - that rendered a pristinely crisp image before service - came back with mushy rendering lacking microcontrast and with uneven sharpness, as if the coating was damaged or (depending on how paranoid I'm feeling in a given moment) front element swapped out for a less mint one. No way to prove anything or other remedy but writing it off and buying a replacement in the possibly unreasonable hope (because these are vintage) of finding one as good - expensive learning experience. At least it sounds like your problem may be fixable - good luck!
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Old 10-10-2018   #11
rfaspen
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I would be unhappy if my lens came back performing at a lower level.

I am very picky about who I will allow to service my Leica gear. I suspect a lot of camera repair shops are capable of dealing with most SLR's, but they probably shouldn't take in Leica stuff. It is deceptively simple stuff, but not really.

I'm not sure who to use in your area (Europe?), but you can get solid recommendations from others here at RFF for a Leica specialist repair person. There are several.

I know it will be an extra cost, but you may want to send the lens to one of the Leica-specialist repair people (as recommended here on RFF) to make the lens right. I am fully confident that my repair person in the U.S. (DAG Camera Repair) can find and correct any problem in my Leica lenses. He specialises in Leica, and has the training and specialized equipment to properly work on my lens. Absolutely worth it to me to send the lens to him in the first place. For non-digital stuff, I always use him before even Leica themselves.
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Old 10-11-2018   #12
lukx
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Thanks for the replies.

Quote:
It is possible that the lens is shimmed (thin pieces of metal are put between the optical part of the lens and the focusing mount of the lens to bring the optics in the right position). If that is done wrongly (if the shim is too thick) the lens will not be sharp at infinity. That will be an easy repair however: remove the shims.
Wouldn't a wrongfully shimmed lens have focusing issues at all distances, at least when using a rangefinder and relying on the rf patch? A wrong shim would have the lens always off by the same percentage, wouldn't it?
It is an intriguing thought, checking for the shims. Not sure if I should do it on my own, though.

Quote:
Pray he was not the one who ground the cam. [...]
However the little "dip" on the cam is not there. Someone screwed this lens up.
So you have looked at the images of my lens and think the cam looks wrong/tampered with? Would you say it looks off? I don't think he did anything to it, at least I did not request any work be done to the focusing mechanism. But it is possible that some else worked on it at some point.

Quote:
I am very picky about who I will allow to service my Leica gear. I suspect a lot of camera repair shops are capable of dealing with most SLR's, but they probably shouldn't take in Leica stuff. It is deceptively simple stuff, but not really.
The guy I took it to does a lot of commissioned work for Meister Camera, the official Leica dealer in town. I went to another shop and he said he can probably do no better work than the guy I dealt with. I could, of course, see if I find another good service person within the EU. Cameraworks in the UK for example. But then I'd pay double.

I will probably unscrew the optics block and have a look inside, as this seems fairly easy to do with my lens and there is a good Video on YouTube on this. If this yields no helpful information, I will talk to the repairman and give him a detailed rundown of the symptoms (again). Maybe he will agree to have another look or refund me some of the money paid for the lens servicing.
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Old 10-11-2018   #13
Roger Hicks
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Leicas are actually quite simple cameras to repair. Source: more than one camera repairer.

Lenses, not so much.

Cheers,

R
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Old 10-11-2018   #14
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Having re-read your post probably isn't the shims if all it is off at is infinity, but I've also never tried checking infinity at anything over a mile as I don't take pictures of anything really that far away and even if I did the enlargement to see anything at 2-3 miles way would be such low resolution it wouldn't matter.
If it was a 500mm I would be worried, when I re-shimmed my 35mm Summilux I just set the focus point at four meters-ish and let distnace/depth of field take care of the rest.
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Old 10-11-2018   #15
Erik van Straten
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Quote:
Originally Posted by lukx View Post

I will probably unscrew the optics block and have a look inside, as this seems fairly easy to do with my lens and there is a good Video on YouTube on this.
I would do this too, but look carefully to the video on YouTube. You should use the same tools.

With M-Leicas, always check the focus of a lens on different bodies. M-Leicas can be adjusted for the distance setting. For example, the roller (that touches the lens) has a large screw in the middle. This is an eccentric screw with which the distance setting can be adjusted. But beware, the distance gauge of the M-Leica has even more setting possibilities.

If you want to adjust the roller, you need a slanted screwdriver.

Erik.
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Old 10-11-2018   #16
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Quote:
Originally Posted by Erik van Straten View Post
I would do this too, but look carefully to the video on YouTube. You should use the same tools.

With M-Leicas, always check the focus of a lens on different bodies. M-Leicas can be adjusted for the distance setting. For example, the roller (that touches the lens) has a large screw in the middle. This is an eccentric screw with which the distance setting can be adjusted. But beware, the distance gauge of the M-Leica has even more setting possibilities.

If you want to adjust the roller, you need a slanted screwdriver.

Erik.
This sounds like you're talking about adjusting the RF in the camera body. I think we agree that's not likely at issue here.

But. the advice about using the correct tools when opening the lens is very good advice. I have accumulated quite a collection of specialized tools over the years because I have learned (the hard way ) that these tools are not luxuries. (Yes, I am aware of the possibilities of making your own specialized tools, I include those as part of my collection too). Anyway, be careful and attentive and know when to stop and back off, saving the repair for someone with better knowledge, skill, tools, etc. At least, that's what I've learned to do in my case.

I suspect there's something amiss with your lens. I don't know about this ground cam suspicion. Many lenses leave the factory with a ground section of the cam as a factory adjustment to make the lens register and focus correctly. Leica has special equipment and people to do this. Many of my lenses show that adjustment (ground area).

Seems as likely that the lens was put back together not quite right. It could be as simple as some fluff or dirt found its way into the lens keeping a section from fully screwing in to its completely seated position. I've certainly had that before. Once it was a few fibers from a Q-tip that found their way into a threaded section. Made the difference.
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Old 10-11-2018   #17
Erik van Straten
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Quote:
Originally Posted by rfaspen View Post
This sounds like you're talking about adjusting the RF in the camera body. I think we agree that's not likely at issue here.
Indeed, but you'll need more than one body to check the focus to exclude the possibility that the rangefinder of the camera is off, so you must first adjust one of the two bodies you are using to get them equal, with another lens of course.

Erik.
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Old 10-11-2018   #18
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The lens cam looks pretty much perfect. As for the aperture witness mark being slightly clockwise, that amount of rotation can be accounted for by a few extra ounces of torque when tightening the optical block of the lens back into the focusing helicoid. If it were missing a shim, the mark would be farther left (clockwise if looking at the lens from the front.) A thin shim will usually account for 12 to 15 degrees according to that mark.
Regarding the focusing action being a little less than perfect towards infinity, like was said even a tiny bit of dust can cause it. It can prevent movement in one or all of three places. The obvious one people go to is the helicals themselves. The other ones are to keep the assembly from rotating. I have found the biggest offender to be the locking ring at the back of the optical block which is actually a part of the helicoid assembly. This is the thick, heavy black ring at the back of the rear element that doesn't rotate when the lens is moved in and out. Over three 50 Summicrons I have found this to be the cause of binding. The clearance between this locking ring and the inner helical is about as wide as thin aluminum foil. You can stick a bit of foil or a very good fine sable brush in that gap to clean it out (very good brushes don't lose their bristles.) Also, a very slight overtightening of this ring will cause the lens to bind at infinity. I had this problem that drove me nuts in rebuilding my DR Summicron. It is fixed in that position with a dab of shellac or paint or loctite on the threads. It must be set up properly to allow the helical to spin freely and through its full travel but not to do so loosely. If the ring is not set with a thread adhesive, it can either tighten or loosen itself. Mine loosened inside the camera and started the lens knocking a bit. I tightened it down then the lens locked up at infinity. That's when I found out it is a kind of direct impingement damper which both holds the helical in and creates the smoothness of focusing. It needs to be perfect to work well.
Otherwise your lens looks great and you should enjoy shooting it.

Phil Forrest
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Old 10-12-2018   #19
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Quote:
Originally Posted by Phil_F_NM View Post
[...] I have found the biggest offender to be the locking ring at the back of the optical block which is actually a part of the helicoid assembly. This is the thick, heavy black ring at the back of the rear element that doesn't rotate when the lens is moved in and out. Over three 50 Summicrons I have found this to be the cause of binding. The clearance between this locking ring and the inner helical is about as wide as thin aluminum foil. You can stick a bit of foil or a very good fine sable brush in that gap to clean it out (very good brushes don't lose their bristles.) Also, a very slight overtightening of this ring will cause the lens to bind at infinity. I had this problem that drove me nuts in rebuilding my DR Summicron. It is fixed in that position with a dab of shellac or paint or loctite on the threads. It must be set up properly to allow the helical to spin freely and through its full travel but not to do so loosely. If the ring is not set with a thread adhesive, it can either tighten or loosen itself. Mine loosened inside the camera and started the lens knocking a bit. I tightened it down then the lens locked up at infinity. That's when I found out it is a kind of direct impingement damper which both holds the helical in and creates the smoothness of focusing. It needs to be perfect to work well.
Otherwise your lens looks great and you should enjoy shooting it.

Phil Forrest
Thank you Phil for this insight. I have ordered the correct rubber stopper that should let me unscrew this ring. This operation would be necessary for any other investigation into this issue, so I am curious to see if that ring alone (plus checking for dirt/dust) could be the culprit. It would make sense insofar as my repairman specifically stated that he hasn't done any work to the helicoid mechanism. He might have just made a mistake when putting it back together. I will report back with my findings.
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Old 10-18-2018   #20
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So, after trying for quite some time I have given up for now.

I unscrewed the retaining ring in an effort to then be able to unscrew the optical block. After removing the retaining ring, I could not for the life of me get the lens block separated from the helicoid. I couldn't unscrew it by hand. So I used a rubber gasket. But the gasket only unscrewed the front element. The rest of the lens block still sits tightly in the focusing system. Once the front element is loose, there is nothing to hold on to left. Only the aperture ring sticks out, but I fear that I will break its tiny screws or even the whole mechanism if I hold onto that while trying to unscrew the block.

I did go into the lens from below. Once the retaining ring is off, the cam can be removed. Once that is out, you can take out a flat shim and three pins that keep the whole unit from turning. With these out, another large ring can be taken out that limits the turning motion of the helicoid. Once these parts are out, the lens and helicoid spin freely. This is a point where setting a mark would have been helpful. Of course I figured that out after the fact.

I gave the parts a cleaning since there was some gunk in the mechanism that could very well have limited the focusing motion. It was tricky to get it all aligned again when putting it back together. But I figured it out.
I have the lens back together now. The rangefinder seems to align better at infinity. The focusing action towards infinity is smooth again. The gunk-removal might have helped with that.
But when I took the bottom of the lens apart, I seem to have moved some dirt into the grooves of the helicoid or other places. Turning the focus ring now has uneven resistance toward minimum focusing distance. This is a bummer.

The aperture mark is still off by the same amount. I unscrewed the front element once it came loose during my efforts to unscrew the lens block. I cleaned the threads and put it back in. In order for the mark to align with the numbers on the ring, I'd have to screw it in more tightly than I am comfortable with/capable off.

With my twisting and turning, I have removed more of the white paint on the distance scale. It is hard to read by now, which annoys me greatly.

My findings summarized:
I learned that I have a lot to learn as a lens repairman. I learned a lot about my lens. Not all of these findings are good. The helicoid needs a professional cleaning. The binding of the lens block to the helicoid must be solved. I myself do not want to work on the helicoid while the lens block is still attatched.

For reference, I used this video as a help. It is very helpful in gereral (as is the whole channel), but it could not assist me with my particular issues.
https://www.youtube.com/watch?v=Wepbwbq4oMg&t=505s
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