Problems with 502

[a_ciel]

I'm a new M6 user, and have a question about a my 50 mm summicron lens. Sorry about asking it in this section, but the lens section hasn't had much activity.

I recently got a 50 mm f/2 lens(#3908XXX). It's a great lens optically, but I have been having a problem lately with the focusing ring. It feels right on the infinity side, but when I try focusing from 5 feet down to 2.5 feet the ring is noticably harder to turn and seems to drag and/or stick a bit. The lens focusing was fine when I first got it, and I've really taken care of it.

This lens is still under warranty. I'm probably going to wind up sending it to Leica for inspection, but I'd like to ask if anyone has an idea of what the cause might be. Has anyone in the forum ever had a problem with a lens sticking due to heat & humidity?

 

[lstl]

I have the same problem with my 50mm Summicron (chrome, and purchased new in 1999). Mine "sticks" at around 3 feet -- not so badly that I can't turn the ring, but enough that I have to fight that little bit of friction to get it into the exact position. The force needed to overcome the extra friction causes you to overshoot the mark, back and forth, back and forth. It's very annoying in a $1,000 lens! As you can tell, I never took it back to be re-lubed or repaired, so all I can offer you is sympathy. I live in the San Francisco Bay Area and my lens has lead a pretty easy life -- no extremes in heat or humidity. It is, however, the chrome version -- don't know if that's a clue. Is yours chrome or black?

 

[a_ciel]

Larry,

My summicron is the black version. Although I don't use the 2.5 to 3 foot range much, I agree with you...the problem with extra tension/sticking is truly an annoying problem on a lens that performs so well optically & costs so much. Granted, this can be corrected if I send it to Leica, but I've only had it for about 6 weeks!!

It's exasperating to focus on something and get close to alignment and then - because of the sticking - overshoot completely and have to recompose.

I'm in New York...not a bad climate, but it's been very humid here lately. Maybe this has an effect on the metals.

 

[lud44]

Hi Larry, Bryan,

Have you similar problems with other lenses on the same camera body?. This reminds me when I got my Leica IIIf with a collapsible 50mm Summicron. It was rather stiff until completing 3 or 4 rolls. Very interestingly it focused always as butter on my second IIIf body

Cheers, Luis

 

[a_ciel]

Luis,

The 50 mm summicron is my first - and so far, only - Leica lens. I put through about 10 rolls of film with no focusing problem. Then I started to notice the difficulty focusing at closer distances. I hope this is something that is considered a minor repair (CLA).

 

[lud44]

Bryan,

I completely agree this behaviour, from a 1,000 Euros lens, is a nightmare. Why not going with the lens and camera to a shop and then try the lens on another Leica body?. It's clear that either the lens or he body has a minor problem. I think it will be easily solved.

Cheers, Luis

 

[david40]

> Bryan, my old Summar lens (which cost quite a lot less than oyur Summicron! used to stick. I reckoned the problem was simply lack of use. It's freed up and is now nice and smooth.

 

[tbc]

I don't think that a Leitz lens should do that. Their promotional literature describes their quality as including dissimilar metals in the focus helicoid, Leica-spec greases, meeting MIL standards, cold and hot weather tolerance, etc. I would have this repaired under warranty. I have a 50 2.8 Elmar which did not focus smoothly. The old grease had gotten hard. Because I could access the threads from the back, I carefully cleaned the focus helicoid. Then I lubed it VERY SPARINGLY. It has been several years since I have done that, and the lens still focuses great.

I have experimented with a variety of greases, and light white grease seemed to work well. However, it seems to be affected by heat and separate, which means that you may get oil (separated grease) on the diaphragm blades. I don't use that anymore. I found a grease called LaBelle 106, plastic compatible, light viscosity so that lenses with tight tolerances (as Leica) focus easily and smoothly. The last lens I did was an old Super Ikonta B, which now focuses like new. So far, no problem with grease separation. I could test the grease by putting some on a piece of metal and letting it sit in the sun. The grease in the container has not separated. I would try lubing the lens only if you're somewhat handy. And, of course, the lens is out of warranty. LaBelle greases are available usually at Model Railroad hobby shops.

Ludwig mentioned it might be something in the body. Test it by removing the lens and then working the focus ring.

There is a quick and dirty way to clean a focus helicoid. If not bad, you can insert a business card between the focus ring which will clean some grit, etc out of the threads, along with excess grease. Hold the lens so that the debris, however small, will fall out (down) out of the lens. Again, be careful not to scratch the body of the lens.

Hope you get the lens to focus as it should. Tom C

 

[dodger]

> The diffculty with using easily available greases for relubing focusing=20 > helicoids yourself is that the don't contain the long springy molecules th= at are=20 > important for that really smooth feel. And further to that there is also t= he=20 > risk of the volatiles in non-specialist greases condensing on the lens=20 > elements. Even back in the 40's Leitz were using a lubricants which inclu= ded whale=20 > oil (low volatiles) and aluminium stearate (long springy molecules). =20 It's disappointing that a =A3600 lens should exhibit stickiness from brand n= ew=20 - I can speak from experience, my 50 Summicron did as well. But after some u= se=20 it cleared up and has been spot on since. There has been a lot said over th= e=20 past 20 years about Leica's quality control, and I was tempted not to believ= e=20 it, but I am inclined more towards agreement these days.

 

[lstl]

I'd also hesitate to try greasing the lens myself, particularly since I have no expertise in the science of lubricants. You guys obviously do, so I'll defer to you on that. After posting my last message (about my 1999 50mm Summicron f/2 chrome) I checked the lens off the camera. No difference, so the camera body (a 1967 M4) is innocent. Then I vigorously twisted the focussing ring for about 30 seconds. Fixed! My first thought was that I was simply temporarily warming up the lubricants, but about ten hours have past since that little "repair job" and this morning it remains smooth. That lens gets regular use, but normal haphazard focussing movements were apparently not enough to "unstick" it. I've tried in the past to unstick the lens this way, but never with such dedication. Frankly, it has never been bad enough for me to deal with it as an official "issue". It has been more of a passing annoyance. But I'd suggest some serious, extended twisting for half a minute or more. It's certainly a cheap repair, if it works!