Back-focusing Leitz Canada Summicron

[Geordiepete]

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I have a beloved Leitz Canada Summicron, chrome. It used to be fine then it started back-focussing. All my other lenses, even those that go to f/1.2, have no such problem, so I can rule out my M9 being at fault.

When trying to focus at something miles away, the rangefinder path does not reach coincidence, but stops a few millimetres away. When taking a portrait at typical distances, the back-focus is enough to spoil the shot. My workaround at the moment is to use the lens only for portraits for now and to unscrew the two main lens parts and rotate the outer barrel one full revolution. Then it focusses for portraits perfectly but the RF patch still does not coincide at infinity.

What has likely gone wrong? Not sure if this is the correct term but my guess is that the tabbed flange at the end of the lense that goes inside the camera is not set to protrude enough. Is this something that can be set. Sorry, I don't know the right terms. Is this a flange, a cam, I just don't know.

I've asked Sherry Krauter and some others and mostly they say that they don't want to work on older 90 mm Summicrons if it will be used on a digital camera, because customers usually complain that it's still not focussing perfectly. Well, I think they haven't understood my particular problem and expectations for a repair, but it seems they have made up their minds.

Suggestions and advice, please!

Edited October 4, 2022 by Geordiepete
precision

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[jaapv]

Shifted element ? Send it in for an overhaul. 

[Geordiepete]

Well, Sherry and one or two others refuse to look at it now they know I'll be using it on a digital Leica. I guess I could email again and say I'm using it on my M3, so they won't be put off by the digital complaints with these lenses they've come to expect.

Thinking back, Leica Japan also said they no longer service this lens as they don't have the parts. Leica Germany (still in Solms?) said the same thing. Then Leica London said they'd service it but they quoted an utterly ridiculous price you wouldn't believe! Then they got back and said it would be tricky, as they'd send it to Germany and they (London) weren't sure if Germany could manage it, but they'd try.

But I am 99% certain it isn't a shifted element. Why, because even if there were no elements in a hollowed out copy of the same lens, but everything else were the same, it still would exhibit that mechanical problem of the images failing to coincide at infinity on the focus patch. That's right, isn't it? That is a problem with the mechanical settings on the camera (which I know are fine) and/or on the lens (that flange thingy that protrudes from the mount-end of the lens and which pushes the rotating, levered cam, I think that's what that is called, which moves the mechanism that moves the rangefinder patch).

Edited October 4, 2022 by Geordiepete
precision

[jankap]

My first thought was, that it is a greasing problem. Is the connecting with the roller in the camera via a rod in the lens?

Do you see a difference, if you focus either from infinity or from 1 meter?

It is bad, that you cannot reach infinity.

[a.noctilux]

7 hours ago, Geordiepete said:

Leica Germany (still in Solms?)

In Wetzlar now.

[jankap]

Cannot you find somebody with a Leica with life view? A newer one so to say. That would help to diagnose the problem.

If you screw the lens head out, that is the same as using a ring. 

[Jeff S]

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Did you speak with Don Goldberg (DAG)?

Jeff

[lebanese blonde]

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!

There was a similar thread on the german board recently and i've posted my solution to this problem.

I had a similar problem with a canadian 50mm v4 Summicron. I applied a bit of copper foil as a temporary solution and it works perfectly, so it seems like this is gonna be my permanent solution

The backfocus at about 2 meters was about 3-5cm and a thin piece of copper foil did the trick  

Of course you can send it to Leica but this is gonna cost a little bit.

[Geordiepete]

Thanks for the ideas, folks.

Don Goldberg a while back said 'with lenses that are longer than a 50mm lens with the M digital cameras[, esp. your 90mm] I would say that you would be better off sending your lens to Leica in Germany. That way no matter how the results of your lens would be, you would feel better about it.' So it seems he too was a bit shy of taking it on.

I tried the copper shim trick a while back, but while that can get me a good focus for portrait distance, the focus is very much out on longer distances, and it still doesn't help the inabilty to get RF coincidence at infinity.

It doesn't seem to be a grease problem, besides, it was lubed and adjusted by Will van Manen or his wife in 2017. Since then it has had this problem but I am not saying it is there fault.

Thinking about all this, I examined the bayonet mount again and noticed that the bayonet nearest to the red dot in not perfectly straight. It looks like it has been bent. This is not easy to see, but once seen, it's recognizable. I also notice that my other M lenses when set to have the—darn, I don't know the terms—the flange or something that moves in and out on the rear part of the lens, extending in and out of the camera body, becomes flush with the top of the steel M bayonet mount. On my 90 Summicron, however, the flange doesn't quite extend that far, possibly because of a bent bayonet.

So, my next step is to try to buy the M bayonet ring (is that the correct term?) specific to the 90mm Leitz Canada Summicron. Questions:

How do I describe that specific part? What's its name? Does it have a part number?

Is there a decent chance of buying a used or otherwise inexpensive one (up to about $60)? Where from?

[Geordiepete]

Oh, and unfortunately I don't know anyone with a Leica M with live view.

I think I will end up sending this lens to Don Goldberg. I just emailed him again; last time was 5 years ago, with the same problem!

[TomB_tx]

If a flange "ear" is bent, it is likely from a drop, landing on the back end. That could have impacted the focus cam and deformed something internally. If so a new flange won't help. I'd send it to Don!

[Frase]

From memory there is brass shims at the front of the lens these can be added or taken out to adjust the focus point, I had to adjust a pre asph Summilux 35mm (different lens but same principle) a few years ago after two shops failed to repair it,

[Frase]

Not my video but if you watch this you can see the shims 

 

Edited October 5, 2022 by Frase

[jankap]

Quotation: "I also notice that my other M lenses when set to have the—darn, I don't know the terms—the flange or something that moves in and out on the rear part of the lens, extending in and out of the camera body, becomes flush with the top of the steel M bayonet mount. On my 90 Summicron, however, the flange doesn't quite extend that far, possibly because of a bent bayonet."

There is your problem. The rangefinder mechanism in the lens is defect, not by dried grease, but on a mechanical way.

Edited October 5, 2022 by jankap

[Geordiepete]

28 minutes ago, Frase said:

From memory there is brass shims at the front of the lens these can be added or taken out to adjust the focus point, I had to adjust a pre asph Summilux 35mm (different lens but same principle) a few years ago after two shops failed to repair it,

Thanks, Frase. I separated the front and back parts of the lens, but no shims in there. I think I'd need shims.

[Geordiepete]

12 minutes ago, jankap said:

Quotation: "I also notice that my other M lenses when set to have the—darn, I don't know the terms—the flange or something that moves in and out on the rear part of the lens, extending in and out of the camera body, becomes flush with the top of the steel M bayonet mount. On my 90 Summicron, however, the flange doesn't quite extend that far, possibly because of a bent bayonet."

There is your problem. The rangefinder mechanism in the lens is defect, not by dried grease, but on a mechanical way.

Thanks. Yeah, I'm thinking replacing the flange will perhaps solve the problem. Is that the right word? The flange is the steel mount screwed onto the inner end of an M lens, yes?

Where would one buy a new or used flange for a Leitz Canada 90 Summicron? Would a flange for any 90 mm M lens do just as well?

[roydonian]

20 hours ago, lebanese blonde said:

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!

 I applied a bit of copper foil as a temporary solution and it works perfectly, so it seems like this is gonna be my permanent solution

Where did you get the copper foil?

[jankap]

1 hour ago, Geordiepete said:

Thanks. Yeah, I'm thinking replacing the flange will perhaps solve the problem. Is that the right word? The flange is the steel mount screwed onto the inner end of an M lens, yes?

Where would one buy a new or used flange for a Leitz Canada 90 Summicron? Would a flange for any 90 mm M lens do just as well?

Why don't you ask Wil van Manen? Perhaps it is not even necessary to send the lens head to them. But, the lens head and the lens mount belong together. It could be, that this is more critical with short lenses. 

Each lens has its focal length (inclusive of the decimals behind the decimal point), for example for a 90er: 90.15 or 89.25. For the rangefinder mechanism, this figure must correspond to the thread of the distance adjustment. At Leica, these parts (head and mount) are matched together as well as possible, formerly manually.

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Hallo,

Look here: Leica M

[Geordiepete]

1 hour ago, jankap said:

Why don't you ask Wil van Manen? Perhaps it is not even necessary to send the lens head to them. But, the lens head and the lens mount belong together. It could be, that this is more critical with short lenses. 

Each lens has its focal length (inclusive of the decimals behind the decimal point), for example for a 90er: 90.15 or 89.25. For the rangefinder mechanism, this figure must correspond to the thread of the distance adjustment. At Leica, these parts (head and mount) are matched together as well as possible, formerly manually.

I was considering that. Anyway, good news for now is that Don Goldberg has agreed to fit a good used flange on it and to repair the focus.

[lebanese blonde]

vor 3 Stunden schrieb roydonian:

Where did you get the copper foil?

I bought it at the hardware store here in germany. Actually I bought it for my garden to save my salad from snails, because snails avoid touching copper.