Collapsible Summicron

<p>I have 50mm collapsible Summicron M mount from about 1957. This lens has become one of my all time favorites. The casualty portraits I take of friends and family look great. But I have one small issue with it. The front part of the lens tends to rotate when I rotate the aperture ring. Let me put it an other way; after extending the lens and rotating it into position it does not "lock". There is no click or any other sense that the lens is locked in the extended position for taking pictures. Is there something wrong with my lens? Its the only collapsible I have ever used and since its much older than me I have never used a new one from the period.</p>

<p>Take the lens off that camera, and look at the back of the lens barrel, the part that slides out, while it is in the collapsed position. There are three curved strips of brass along the rear edge. These three strips are what prevent the lens from unlocking. In some cases they have been pushed too close to the lens barrel, so they do not present enough friction to prevent the lens from unlocking.<br /> <br /> Take a thin strip of plastic (I caution you not to use a steel knife, or a Swiss Army screw driver, as they can mark the brass), and gently push the end of the strips outwards, less than 0.2mm. Do this in increments and then try to lock and unlock the lens. It should work.<br /> <br /> Let me know if this is not clear and I'll find pictures.<br /> <br /> Best of luck!</p>

<p>I'm looking at my 1954 collapsible Summicron and trying to figure out what your problem is. The lens doesn't "lock" into the open position, like a modern lens locks - it just sort of tightly snugs into position. Does your aperture ring move smoothly or is it hard to turn? I'm thinking perhaps either when you turn it you are inadvertantly resting your finger on the knurled part of the lens housing itself and turning the entire lens from its "locked open" position, or that the aperture ring is snugged too tightly forward against the knurled ring surrounding the lens itself. Basically it sounds as if something is too tight and either needs light lubrication or a slight alignment. The lens should not rotate as you move the aperture selection ring.</p>

<p>Yes, mine just snugs into place. I can move the aperture ring all day, focus with no problems, and everything stays put. I suggest taking it in for servicing and cleaning.</p>

<p>Thanks for all your responces they were all very helpful and fixed my problem (for now :-)<br>

Vic; Now that i know what to look for it was an easy fix. The 3 tabs were worn and smooth with the bottom of the lens. With a very hard plastic tool I was able to bend then out just a pinch until I could feel that they were not smooth (like setting the blade on a wood plane ). Now the lens stays put when in use.<br>

Stephen; Yes I do then to grab the wrong collar. This happens so much that I now set the aperture with both hands. With one on the lens body and the other on the aperture collar. I use hand held meters; I set the aperture once for a given scene. And my aperture blades are a bit sticky but I do not see any oil on them. I'll send the lens in for a CLA after vacation season.<br>

One thing that I have notice about the aperture blades on this first generation Summicron is that the gap from f2 to 2.8 is about 10mm while the gap from f11 to f16 is about 3mm. The aperture scale is not evenly spaced like the modern Leica and Zeiss lenses.</p>

<p> </p>

<p>My 1954 collapsible Summicron exhibited this behavior because the aperture ring was dry and needed lube. My technician corrected that problem along with a CLA of the camera body.</p>

<p>The aperture ring should move smoooooothly. If there's any suggestion of friction (as opposed to the detents), it's CLA time. Not quite loose enough for "one finger" operation, but close.<br>

The mechanical fit of the aperture ring on the Summar, Summitar, and collapsible Summicron is very tight, and requires gentle lubrication. If the lube goes bad, or accumulates dirt, it can turn to goo that makes the ring nasty hard to turn.</p>

 

<p>I hope that you rarely take "casualty photos" of your friends and family, unless they are particularly accident-prone!</p>

<p>John, work it out: the 1954 Collapsible Summicron is a wonderful lens -- I love mine.</p><div></div>

<p>John, The collapsible has become my favorite also. I have had work done to mine. I had John VanStelton recoat it and have had DAG CLA it for good measure. It is now like new and very smooth as John Shriver says it should be. I just love the lens. I will try and attach a photo, Robbie.</p>

<p>One more time..</p>

<p>I will try one more time!</p><div></div>

<p>I had trouble with this lens. It was prone to flare. Do you have that problem?</p>

<p>Every Summicron has flare. Some more,the collapsible the most. The look of the image esp portraits is what i love. Pick your battles carefully. This lens while a star is no Super-Takumar. It is very sharp and has low contrast, worthy qualities when i lived in South Africa and later Southern California. Now in Canada, the flare somewhat more irksome. Would i sell it? No.</p>