40mm Summicron-C aperture problem

[Dan Daniel]

I just bought a 40mm Summicron-C. In good shape, showing wear but optically clean. It was supposedly just overhauled. I'm noticing that the aperture ring clicks in some strange positions, and I was hoping that someone here with the same lens can tell me if this is right or wrong.

Basically, there is no definite CLICK at f/2.0. It stops and stays there, but the click is a bit to the right. And at f/16, there is a definite click PAST the indicator number.

Photos:

Last definite click when going to wide open:

The aperture ring will stay at this point shown, and this is the maximum travel point in this direction. But there is no definite click at this position:

And then this shows the final click stop going in the other direction. There is just the slightest bit more travel room before it hits a hard stop and won't rotate any more:

All in all, I get the sense that the scale is one click stop (one-half aperture stop) offset. That it SHOULD stop at f/16 and that there should be a definite click stop at f/2.0.

If anyone with this lens could take a minute to compare your clicks and limits to my photos, I'd really appreciate it.

And if anyone knows if it is simple to correct, also much appreciated. I am comfortable opening up the lens, and I've seen the web page giving directions, but if there's nothing I can do once inside, well, I won't bother.

Thanks much!

 

[Frontman]

My 40mm Summicron stops right on the numbers, but I have a 50mm Summicron whch is a little off, just like in your photos. It does not affect how the lens works, so I don't worry about it.

 

[Vickko]

From the photos, the "dot" is misaligned from the triangle of the focus index.

Did you look here?
http://www.jumboprawn.net/jesse/cams/gear-profiles/leica-summicron-40mm.html

I'm pretty sure that if you take the head off, you can re-align the whole thing.

 

[lam]

I had a 35 summicron that did this, yes just unscrew it and rescrew it back on fixed it i think

 

[yossarian123]

Mine does the same thing. I've seen no negative impacts to any shots taken with it so I haven't worried about it.

 

[Mark C]

From the photos, the "dot" is misaligned from the triangle of the focus index.

Did you look here?
http://www.jumboprawn.net/jesse/cams/gear-profiles/leica-summicron-40mm.html

I'm pretty sure that if you take the head off, you can re-align the whole thing.

What has been mentioned in this thread will align the dot better with the distance indicator mark, but won't fix the issue with the aperture numbers being off.

 

[Dan Daniel]

Thanks for the comments and suggestions. I'll give some thought to opening it up and aligning things better.

Anyone know if relaxing the indent ball bearing will allow rotation for getting the clicks in line with the numbers?

 

[Vickko]

Relaxing the indent will only make the clicks softer.

One of the rings, the one containing the location indents, or the ring numbers, needs to be re-oriented.

Leica was often good with building in adjustability.

You should be able to find it, if you take it apart.

Anyone know if relaxing the indent ball bearing will allow rotation for getting the clicks in line with the numbers?

 

[Mark C]

Relaxing the indent will only make the clicks softer.

One of the rings, the one containing the location indents, or the ring numbers, needs to be re-oriented.

Leica was often good with building in adjustability.

You should be able to find it, if you take it apart.

Yes. The detents are correct anyway, not the numbers. I don't have that lens in front of me now, but the sleeve the numbers are printed on should turn to allow you to align with the dot better. The picture on the disassembly page linked above looks like there might be set screws, but I really don't know.

 

[Dan Daniel]

UPDATE: I got the indicators in alignment- f/stop numbers aligned to detents, and main f/stop dot aligned with focus index.

Numbers aligned to detents: on the front of the lens is a single small screw, between the end of the serial number and the 'S' of SUMMICRON on my sample. Loosen this and rotate the 'dot' part until it aligns with the numbers. Test to see if the end points are correct. On my sample, this required a small rotation clockwise, which revealed a previous indent below the ring, probably from factory installation. Be careful about this screw- it's a very small and short set screw. Work over cloth in case it drops.

DOT aligned to focus index mark: loosen the retaining rig on the back of the lens. rotate the lens elements until the DOT is aligned. Tighten retaining ring. That's it.

Thanks again for the comments and ideas from everyone.

 

[KenBPhotos]

That's odd, I had the same problem so I unscrewed that screw in the front between the serial numbers and summicron and it would not move. My f/2 actually goes to the left of the dot instead of the right on yours. I took the screw out and looked in and it definitely had a mark there where I think the factory had it originally so I probably don't want to move it anyway, but I think it burred out on the edges preventing me from rotating the ring with the dot on it. It would NOT move. I think I need to loosen the whole barrel and move the dot to align it. It looks a hair off to my eye.

My questions is, what retaining ring do you loosen? I see the barrel that sticks up with the two indents for a spanner and then below that is the ring that's slightly offset. I noticed some marks there like that was what was taken off but I'm not sure and don't want to push anything. Which ring needs to be taken off to separate it? It's never stated at that site that everyone references.

 

[Dan Daniel]

My questions is, what retaining ring do you loosen? I see the barrel that sticks up with the two indents for a spanner and then below that is the ring that's slightly offset. I noticed some marks there like that was what was taken off but I'm not sure and don't want to push anything. Which ring needs to be taken off to separate it? It's never stated at that site that everyone references.

I'm not certain if I understand what you are asking, but if you are referring to the retaining ring on the back of the lens, it is the black ring inside the brass ring, the one that sticks up and has two notches for a spanner wrench.

I've tried to take a photo, but no macro handy and black on black isn't very helpful. Excuse the quality. The toothpicks are at the two notches that I used to remove the lens element block-

Once this black ring is removed, the block holding all the lens elements slides forward and out. Best as I can tell, there are no critical positioning issues for re-assembly.

Not sure what to say about your aperture dot. I didn't get a lot of motion, and it did want to bind. But once I saw that it was in position and that there was a second indent for the set screw, I put the set screw back in and called it a day!

 

[KenBPhotos]

Thanks, so it IS the raised ring piece. If you look right below it (looks like left tooth pick is on it) there's another ring around the outer edges of the cylinder piece with two notches. I wasn't sure if that was the retaining ring or if it was the large black cylinder piece. How did you get it off? Did you use needle nose pliers or the spanner wrench? I'm not sure where to get the spanner wrench tool and I'm pretty nervous using needle nose pliers like I've heard people do. One slip and you're majorly SOL! Also, why do you think the aperture dot piece is not spinning after removing the screw in the front on my copy? Maybe I misread what you said but I thought it would spin after removing the small set screw.

 

[Dan Daniel]

Thanks, so it IS the raised ring piece. If you look right below it (looks like left tooth pick is on it) there's another ring around the outer edges of the cylinder piece with two notches. I wasn't sure if that was the retaining ring or if it was the large black cylinder piece. How did you get it off? Did you use needle nose pliers or the spanner wrench? I'm not sure where to get the spanner wrench tool and I'm pretty nervous using needle nose pliers like I've heard people do. One slip and you're majorly SOL! Also, why do you think the aperture dot piece is not spinning after removing the screw in the front on my copy? Maybe I misread what you said but I thought it would spin after removing the small set screw.

I use needle nose pliers with ground-down tips for my spanner wrench. Tricky. I'll put a masking tape cover over the glass before doing this the first time on something in case it's tricky and I slip. Well, be careful or find another way?

When I adjusted my aperture dot, I simply had to turn the ring maybe 5-10 degrees? Then I saw the factory (?) set screw divot, which happened to be the right spot. I noticed that there was limited travel, but I didn't take the time to see how to make it go further or such. My limited experience on lenses says that once I get things right I need to STOP before I go too far and can never get back.