35mm Frames Lines with a Summicron 50mm

David Murphy

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I'm pretty much a newbie to the Leica M world, but I've got a Collapsible Summicron (M) that brings up the 35mm frame lines when it's mounted on my M2. Can someone tell me why?
 
Is there an adapter for SM to M on it? If it has the adapter on it . it maybe for the 35 and 90 FLs.

Bob
 
I'm pretty much a newbie to the Leica M world, but I've got a Collapsible Summicron (M) that brings up the 35mm frame lines when it's mounted on my M2. Can someone tell me why?
Is it a screw-mount Summicron with the wrong adapter attached?

[Edit: Ah, Bob just beat me to it]
 
OK, the lens is a Summicron M collapsible (not an adapted LTM Summicron). I also found that if I release the little chrome locking tab on the body that latches the lens in place, it will turn just a tad beyond that and then I can activate the 50mm frames by pushing the frame selector to the middle position (and it stays there). This is not right of course. I suspect wear on the lens or perhaps maladjustment of the frame selector mechanism. I'll take some photos and post them here.
 
If I use a Leica-made 2.8-5cm LTM->M adapter on the M2 the 50mm frame lines come up just fine. I suspect the lens is the problem. The machining of the adapter is very similar to the lens -- slight differences on the blades of the bayonets.

Just a question: Does the clocking of the position of the milled tab (in the lens flange) determine which frame lines are activated?

Here are some photos of the back of it:

sum6.jpg


sum5.jpg


sum4.jpg


sum3.jpg


sum2.jpg
 
Hi, Dave.

I believe the smallest lug on the rear of the mount (the cylindrical ring) is the one that activates the frameline mechanism. Another way to put it is in reference to the RF-coupling ramp, which is the large milled "notch" in the 12-2 o'clock region of your last photo above. The frameline activator lug is the one immediately to the left (CCW when looking at the mount) of the gradual-slope end of the ramp.

Someone please correct me if I'm in error; I've picked up this tidbit from goodness-knows-where. As for the milled pocket on the rear surface of the flange, I think that's the receiver for the lens lock; in this way I don't think its clocking is variable with regard to the frameline lug.

In actuality, it's the length of the lug that determines the activated framelines; for example, folks who want the 40mm Summicron to bring up the 35mm framelines on their M-cameras will file material from the leftmost (CCW) extreme of this lug, essentially the blunt end.

I think I'm prattling on because it's late. Apologies for any errors; good luck with the lens, the collapsible Summicron is a joy to shoot.


Cheers,
--joe.
 
What Joe said.

I've attached a pic showing the metal 'thing' that selects the framelines. Does this show any wear/damage consistent with someone having at it with a file or somesuch (although why anyone would want to do that I don't know).

Do other 50mm lenses/adapters bring up the right framelines?

If you look in the lens mount with the lens removed you should see a blackened flat prong on the right (looking from the front of the camera). Does that move OK as you move the frameline selector lever?
 

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Would have attached a photo of the back of my collapsible Summicron M, but what Kully has done is enough. In your third and fourth photos, David, what Kully politely calls the "thing" appears to be scratched or even gouged.
 
The cam mechanism on the camera is present and seems ok. I think the problem is that this bayonet wing on the lens is either very slightly bent or worn. I may be able to repair it (I have some access to machinists and a machine shop). As I stated before, a 5cm LTM adapter activates the 50mm frame lines just fine. I will us a caliper to measure the dimensions on the lens mount and try to understand the discrepancy and how to ameliorate it.
 
David, remember that you'll need to add not remove to that 'flange' (don't get to use that word often), a few fractions of a mm at a time is all you need.
 
Lots of good descriptions here, but I have to thank Kully for reminding me why after years of amateur practice, my images still don't "tell stories": I'm apparently all about the words.

Kully's annotated image is worth 1,000 of them - bravo.

Dave, good luck with the lug repair-you should be able to build it up with something like JB Weld or somesuch thing, and then file it back to shape.


Cheers,
--joe.
 
Dave, if you have access to a machine shop or a small dremel you can build up material on the lug. The lug that "keys" in the frame line is the one with a sharp 90 degree "cut" on it. On the pictures it looks a bit "chewed" up and that is probably the culprit. Drill a small hole (0.8mm or so) in to the flat surface of the cut and stick a piece of wire into it and fold it so that it covers the cut. If you want to ensure that it stays in plave apply some silversolder on it ( make a small paper disc that protects the rear of the glass) and then file it flat. Put the lens on (and it will most likely show the 90mm frame). With a small jewellers file, remove material until the 50 frame is shown (do very shallow file cuts as you are obviously close to the correct angle as the frame shows up when you "twist the lens). You might only need to put 1/4 of a millimeter on it to engage properly.
It sounds more complicated than it is. I like using the wire as an anchor for the silver solder - particularly when you are filing on it.
 
Joe, I nlooked at the pictures. I know which bayonet lug surface is involved, having done the file work on a 40mm Summicron. I didn't see any obvious damage or wear; but if you are satisfied that you know now which lug it is, looking at its "leading edge" surface and see if there is still chrome, or if brass is showing through. If the chrome plating is still there, I would suspect that the lens is not the culprit. I have to file fully through the chrome plating to get the 50mm frameline to go away; and I have to file even more before the 35mm frame comes into view. The amount of material removed is not great, but it is significant. I just measured the flat part of the lug on my 50mm Collapsible Summicron (M-mount) and the length of the same surface on my modified 40mm Summicron. The difference is 1/32 inch. The 50mm measures right at 1/8" and the 40mm modified one measures about 3/32" about a 1/32 difference. Removing any less than that 1/32 inch was not enough to bring up the 35mm frames. So unless it looks like the chrome is all gone from the lug end, I wonder if the frameline mechanism is out of adjustment. I read what you wrote about the adapter bringing up the 50mm frames, which would argue that the camera is not the culprit; but could you check to see if there's any bare brass at the lug end? I tried to compare the photo with my lenses, but the scale is different, and I'm not sure if that lug looks too short, or not.
 
Collapsible Summicron Now Fixed!!

Collapsible Summicron Now Fixed!!

OK guys thanks for all these good ideas -- it's been a great learning experience (I'll file some of these tricks away for future use).

My camera tech fixed the lens today and he thinks he knows what happened too. The problem was that the notorious little bayonet blade that actives the frame selector mechanism was bent inward ever-so-slightly, probably because the lens was dropped at some point in its life. In essence the outer diameter of the relevant bayonet blade (which acts as a cam) was not extended radially enough to do it's job correctly. He took the lens into his shop for a while this afternoon and fixed it -- my understanding is he bent the blade back out ever-so- slightly with precision pliers. Incidentally his name is Edward and he's the proprietor of Whilton Camera in Pasadena -- highly recommended.
 
David, excellent news. It's funny that what seemed to be the case (the lens) kept us blind to the actual culprit (the body). Glad Edward worked it out.

From what you've told me about this fellow, he certainly seems to know what he's about.


Cheers,
--joe.
 
No Joe I'm still not communicating well perhaps, the "culprit" was the lens, not the body. The blade I'm referring to is the flange blade on the lens. In the parlance of your profession (correct me if I'm wrong), the lens flange acts as a "cam" and the mechanism inside the camera that it makes contact with (to select frames) is a "cam follower".
 
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